Overly competitive people
This one is kind of a given. As a disclaimer, I have no problem with people playing the meta, keeping up with it, etc. However, if you come to a locals every week and only ever play the Tier 1 decks, you're probably cancer. Bonus hate points if you show up every week with the 1st place deck from the most recent tournament, no matter what it was. Double bonus hate points if you don't actually know what any non-meta cards do.
I've gone too long with locals too meta-oriented. It sucks for casual players, new players, and generally anyone there to have fun. These people are the ones who you never actually see with a "fun" deck or talking about anything other than meta decks/combo's. The stint between when Grimm Cluster got preemptively rotated out and when Lapis Cluster dropped, my friends and I basically stopped playing in tournaments. Outside of us, locals was essentially nothing but R//R Stealth, with the stray R//R Necrolane here or there. I got asked why we didn't play anymore and I told the guy "We're gonna start back up in Lapis Cluster. The game right now is literally nothing but control, so I could either not play, or pay $7 a week to not be able to play." Random Douche-McGee #7 who was standing around butts in, out of nowhere, with "People are still going to play control after rotation" and then promptly went back to popping children's balloons and stealing candy from babies.
I take no issue with playing to win, or wanting to make your deck as good as possible, but people could at least pretend they're playing the game to actually have fun, rather than stroke their fragile, complex-ridden egos by winning in a cardboard game.
Having to play for both players
If I actually ranked these, there is no doubt this would be #1 on the list. I've played Yu-Gi-Oh, Cardfight Vanguard, and now Force of Will, and this is a problem that has always, and will always, trigger me out of my mind. I don't expect people to know every facet of the game, but common sense just seems to elude most TCG-ers. The only reason I got certified as a YGO judge was so people would have to shut up after I told them they were wrong. Here's just a handful of the hemorrhage-inducing "rulings" I've had to hear, in each game:
Me: "I chain Shadow-Imprisoning Mirror"
Them: "Uhh, I get priority. Hornet gets equipped."
Them: "I can special summon monsters while I control Acid Golem as long as it has materials, because there's a comma after that clause, not a period."
Me: "That's definitely a period."
Them: "No, this is how they ruled it at YCS <who cares>"
Me: "I flip summon <random monster that summons something from my deck on-flip"
Them: "I chain Torrential Tribute."
Me: "Ok, so my monster dies. Now special summon <whatever I got out from deck>"
Them: "No that dies too."
Me: "How? Torrential already resolved before it entered the field."
Them: "That's how it works. That's why people summon something they don't care about when you chain torrential to a summon effect."
Them: "When you check the top 5 cards of your deck with a Grade 3 searcher and you don't get anything, you have to show me. That way I'll know like if you get all triggers or see three Perfect Guards."
Me: "Literally nothing about that is right."
Force of Will
Guy 1: "I attack you with Viviane."
Guy 2: "Ok, I'll be left at 200 after that."
Guy 1: "Ok, I'll quickcast in Escort of the Fairy King so she gets pumped for that last 200."
Guy 2: "You can't do that. You can't quickcast after attack declaration."
Guy 1: "What?"
Guy 2: "It's just how quickcast works."
Force of Will
Them: "I use <some random automatic ability>"
Me: "I'll chase that with <random spell/ability>"
Person 3: "You can't do that. Automatic abilities don't use the chase."
Me: "Your mother should have used a condom."
And that isn't even close to all of it. I can't even begin to explain how much of a headache it is to not only do my part to play the game, think of all my plays, my opponent's possible responses, etc but also have to babysit them and check over every little thing they try to do or say. If I wanted to play for two people I would have just played solitaire against myself. Generally, the people you have to do this to aren't going to give you a satisfying game, so you won't even be having fun. Is it really too much to ask to just know how to read and play the game properly? This kind of borders "I hate people who cheat," which is also true, but I feel "people who conjure up random BS rulings/excuses/explanations" deserve their very own category.
The used car salesmen
These are the bane of anyone looking for a trade. To call on an example, back in my CFV days I was trying to put together a Chaos Breaker Dragon deck, and the card was around $30-40 for a copy, and a guy had just bought a box and pulled one. I went over to trade him, and he saw a few things in my book he needed for a deck he was building. "Ok" I said, "Chaos Breaker is going for about $35 average on ebay right now..."
"Actually he's $40. I could sell him for $40 if I put him up for sale."
"Ok, sure, whatever. This one card you want is $10, this one's $15, and this one's about $10 too."
"Actually that one is only $9 and that other one is only $13."
People who over-value their own stuff, and try to under-value your's as much as possible, aren't worth trading with. The penny-pinchers, who want to get card values down to the exact cent and will refuse to trade unless the values are equal, fall into this category too. And, the king of all these degenerates, is that one guy who won't trade anything unless he can profit off of the trade. One of my friends needed a relatively high-rarity card from a guy who had just pulled one. "I need X card for this deck I'm working on. Do you have any of those?"
"I do, actually." My friend said. "But it's like a $20 promo, and the card I want is only $10. But I've got tons of these so I don't really care. Sure, I'll do that trade."
"But I need 4 of those promos for my deck."
My friend slapped his book shut and walked out.
The poltergeists that haunt your game
The back-seat duelist. The lurker. This person goes by many names, but they all refer to one piece of scum. This is either someone who finished their round early or someone who just came to spectate and didn't even enter the tournament. They float around your game, commenting on every little thing that happened, picking up the top card of your deck to see what you're going to draw, touching everything on your field. Not only do these people dance dangerously close to the "no coaching" rule during tournaments with their snobbish remarks, they're just plain obnoxious. In general, they tend to get a little pompous and think they're just the bee's knees at the game, and usually they're completely wrong. These are the people who will walk over, berate you for not doing a play they consider "obvious," and not even think about the rest of the gamestate or potential counters.
"Lol idiot, why didn't you just use space-time on that Lancelot and kill it when it swung at you?"
"Because he searched out Magic Sweets last turn."
"Well how am I supposed to know he did that!? I just walked over."
There are plenty of reasons you wouldn't want people to touch your cards, and there are people that like to exemplify every possible instance of that, and then some. Some players are unnecessarily aggressive when handling your/their own cards, be they shuffling your deck with enough force to split atoms, or targeting your cards by gracefully shoving their finger through your sleeve, card, playmat, and the table underneath. Some players get that MLG hankering for Doritos and decide to open up a fresh pack just as you sit down and present your brand new, freshly sleeved, pearly white sleeves to them for cutting. Some (weak) people give in to basic bodily functions like sneezing, or scratching their butts, and move to handle your deck immediately after (obviously so they don't waste any of that precious time in the match).
I have a blacklist of people who aren't allowed to touch anything I own, ever. I, very verbally, express my disapproval if someone tries to do any of the above, and I highly encourage everyone else to do the same. If someone isn't going to respect your belongings, you shouldn't respect them.
You knew this was going to be up here, it's the apex of TCG player stereotypes, and unfortunately, it's universally true. A large chunk of people who turn up at card shops neglect basic hygiene, and I often wonder if some of them have ever seen a shower. Seriously, have some self-respect, or more importantly, respect the people around you and don't subject them to that miasma. Some people get the genius idea that wearing tank tops and letting those hairy pits air out will help mitigate the smell. Sadly, they are very mistaken. When the smell of cigarette smoke inevitably gets mixed into that brew, you're left with a concoction of biological warfare-proportions. These people are the reasons we get the bad reputation we do.
A field as cluttered as your MLP-merchandise-filled room
Contrary to popular belief, the playmats of card games actually do have zones on them. Some games, like YGO and CFV, are very strict in their fields and have very stringent zones. Some games, like MTG and FoW, are lenient and just have "field". There are also designated deck zones, graveyard zones, and whatever other zones your game of choice has, and they all have specific locations on the board. I understand people who swap the grave and deck zones (I do it too), keep their Ruler in the center of their mat, or things like that. It helps you unclutter your board, or is just a more natural feel. Some people are left-handed and reverse their field. All of these are understandable and excusable.
Something like "I keep my stones below my deck, above my graveyard!" or "I keep my Ruler above my deck" is not. Not only is that stupid, it causes needless clutter and confusion. The board is set up the way it is for efficiency and consistency: I can, at any give time, look up to see my opponent's field and know exactly where to look to find any given zone I want to look at. Putting your graveyard below your stones instead of your deck just makes me think you're trying some dumb cheating method.
In the same vain, some people just refuse to properly organize their field. I mean I get it, there's no limit to the number of things you can put on the board, and some decks like Fiethsing will have 5-6 regalia, their stones, and 10+ resonators on board. I can get really cluttered, but that's all the more reason to try to keep it in order. I've played against people who have stones separated into three different clumps, some of them are upside down, and their "tapped" cards are askew in some indescribable angle attempting to breach the 4th dimension. Their regalia are all over their field instead of consolidated into one area, and some of their are completely covering others. There's a tower of resonators trying to become Babel 2.0.
Horribly managed fields, on top of making me suspect you're trying to cheat, give me a huge headache. I'm trying to keep track of what's supposed to be where, what entered this turn, what's actually rested or what you forgot to untap because you skipped like 7 phases. This almost ties back into the "having to play for yourself and for your opponent" section, since you're having to pay too much attention and keep track of too much of what they're supposed to be taking care of.
Your sleeves are as broken as your marriage
Sleeves are very, very, very cheap. A pack of Ultra Pros costs like $3-4. There are far too many people who are using what appear to be their very first pack of sleeves they ever bought, and refuse to get new ones. These things have more splotches than clear space on the front, stick together at the atomic level, and transmit dirt and disease into anything they come into contact with. That's assuming they aren't torn to bits (artwork sleeves are the worst in this regard) and have split to the point that it's a scientific marvel how they're still intact.
These things just feel awful to touch. Shuffling them is akin to giving your thousand year old grandma a foot rub, and with how much the cards stick together, you question if your shuffling actually did anything, or if the opponent isn't accidentally drawing 2-3 cards a turn just from cards being stuck together. What's more, even touching them makes you feel disgusting and it feels like you're dirtying your own sleeves just by handling them after touching your opponent's janky garbage pile of a deck. Not to mention the toll it takes on them sliding their deck on your mat to let you cut it.
Tournaments are, generally, a $5 entry. The cards you're putting in your deck can easily hit $20 and $30 values. "I don't have the money for sleeves" is not a valid excuse, despite being the one I've heard most often. If Oscar the grouch here didn't crawl out of his trashcan one week to enter a tournament, he'd have enough to buy a pack of sleeves that will last 2 months (or 2 years, given how long these people use these sleeves).
I don't have a witty title for this one because I was too eager to tear into it. This category encapsulates all kinds of degenerate players, from the "Man I only lost because he drew X" to the "Wow that <random rogue card> is so broken." I'm going to break this category down so I can have ample complaint time for all of its subsets.
The people who go "Oh man, I was going to draw X next turn. I would have totally won next turn!" Ok, but guess what? You lost this turn. My deck was just better and went off faster, or I was better and made more efficient plays. All I hear is "I could have won if I didn't lose!" which just makes you sound stupid. These are the people who are just looking for a scapegoat for their loss, instead of actually thinking about what they could have done better or differently, and that's what triggers me about this.
There are also the people who say "I only lost because they drew X card" or "They only won because I overextended." A common example, from my YGO days, was someone complaining because their opponent drew Dark Hole and nuked their 5-monster board. Does it suck? Absolutely. It's completely legitimate to hate the fact that your opponent luck-sacked into the one get-out-of-jail-free card they needed. But these players never stop to think "Why did I flood the board with monsters and overextend if I couldn't kill them or didn't have protection?" Using all of your advantage without insurance or a backup plan is honestly something you deserve to be punished for, but most people would more easily blame something like luck instead of owning up to their own misplays or bad decisions.
Finally, there are the people who complain about your rogue-tier cards being too powerful. Or mis-attributing a deck's strength to a particular card that beat them. Back in my CFV days, my friend played a Jewel Knight deck (For those of you unfamiliar with the game, it's basically Waifu Paladins that flood the field) and had Divine Knight of Flashing Flame, Samuel as a 1-of in his G-zone. In CFV, you lose when you hit 6 damage, and in a particular game, my friend's opponent had thrown most of his hand down and rushed my friend to 4 damage very early. Thanks to that, my friend was able to flood the field AND have enough resources to use Samuel's ability to deal a damage to the opponent, putting him from 3 to 4 damage without combat, and killed him that turn since his opponent had virtually no hand from rushing. The rest of the day, that opponent was complaining about "The only reason Jewel Knights are OP is because of that card", and other things in the same vain. In truth, that was probably the first time my friend had used that card in about a month.
Now, a certain amount of butthurt is to be expected in a situation like that, and I don't fault anyone for being a little upset to losing to a random card they weren't prepared for. But the players that truly get on my nerves will actually argue with you when you tell them that X card isn't broken. "How is that not stupid OP? It's just a free damage!" Even though no meta decks run it, the deck isn't competitively relevant, or there are easy counters to it. I'm not opposed to someone disagreeing with me about a card's relevancy, but I can't stand it when I explain that a card isn't all that good because every relevant deck runs an out to it or that it only works in certain situations, and someone retorts with some half-baked response along the lines of "but when it does go off it's broken" or "that's only if they see the counters to it." As a side note to this, there are some people who simply have no business actually discussing meta or competitive relevancy (either due to a huge bias for/against a certain card/deck, a lack of mechanical/meta knowledge, or any number of reasons) and those tend to be the most vocal in situations like this. Unsurprisingly, they're the ones that get on my nerves the most.
Welp, that's it folks. This was a pretty cathartic article for me, and I'm sure everyone out there has things they absolutely hate to see or deal with. Did I touch on any of those here? What are your biggest card game triggers?