Don't get me wrong, Modern Warfare 2 is a good game, but some of the stuff that goes on in multiplayer really ticks me off. Luckily, I haven't broken any controllers... yet. :P
 
-Dual 1887's. Who the heck at Infinity Ward thought this was a good idea? "Let's take one of the most powerful shotguns, and give players two of 'em!" Not only do these things have crazy ass range and damage, but you also look like a dweeb when you run with them.
 
-Boosting. Seems like every other free for all match I join, there's two kids in the corner boosting for one thing or another - the worst is when it's a nuke. If you can't get it legit, don't get it at all.
 
-Entering the match when one team is completely dominating. Because we all love joining a team that's getting their asses kicked, right? It's also fun to deal with the other team's two harriers, pavelow, and AC-130. /sarcasm
 
-Entering the match when it's basically over. I never really remember this being such a problem in Call of Duty 4. I'd rather not join a game for the last couple of kills, the last couple of ticks on the clock, or on a couple of occasions, the game-winning nuke. Then I need to sit through the final kill-cam, the post-match scoreboard, and the waiting time between matches for a game I didn't even really get to play in.
 
-"Real" camping. When I say camping, I mean sitting in a shadowy corner with Dual 1887's fixed on one door, and a claymore perched right behind the other door. This is especially bad, because most of the maps in Modern Warfare 2 have tons of houses/buildings.
 
-Glitching. Damn you, javelin glitch!
 
-Big maps in FFA. Sorry, but I don't want to play free for all on Quarry... or Wasteland. It's much too slow paced.
 
-Getting spawned right in front of, behind, or generally really close to an enemy. One of my biggest pet peeves. It really sucks when you start the game right in front of someone, and all they have to do is knife at the start of the match to get a kill (*cough* Rust *cough*).
 
-Painkiller death-streak. Seems like every time I'm a kill away from one of the higher kill-streaks, some guy with painkiller comes and guns me down. There's not really much I can do when the guy has three times as much health as me.
 
 Think there's anything I'm missing? Feel free to post your own!  

I agree with all of those.

"

"

The dual 1887's are what get me most, the range on them is a little mad, not to mention it's just plain weird to see half a team dual wielding antique weaponry in a game set in the near future.

Seems like this game is just not worth playing.

" Seems like this game is just not worth playing. "

I agree with lots of these. 
 
For me, add the ragequitters to the list. I can't tell you how many times my team starts out fine, begins losing a tiny bit, then suddenly it's like enemies are crawling out of every hidey-hole. So I take a look at the scoreboard only to find my team is down 3-4 players because of the damn babies that can't try to come back from a deficit. 
 
They're also the reason you get into matches during the last few seconds; they said, "well I'm going to lose anyway, who cares about the match bonus?" and bailed. Wussies.

if you play domination a lot of these can be avoided...

i know - i heard those 1887 dualies are a nightmare to deal with. 
 
http://www.youtube.com/watch?v=B2IZd26F43I    
 
pwnage. 

" The dual 1887's are what get me most, the range on them is a little mad, not to mention it's just plain weird to see half a team dual wielding antique weaponry in a game set in the near future. "

1887 duals shoot magic fucking rockets it seem, the range on it is frikkin sick, and when you get hit by both shots even when you are somewhat far away you die instantly because of its sick range. Something needs to be done with them

Yup, as stated in other threads, these are faults of the game design and not really the players'. The people doing this aren't really to blame rather the ones that made the game. These glitches, bugs, and general unsporting conduct are encouraged by the "hang back cause we have little health, guns are powerful, and we have the tools and the sky to do so". Balance is off in this game, story short.
 
Oh well, is the only advice I can give haha. Play another game when this one gets to ya. It's the tactic I have to use.

Yeah, I usually turn to Rock Band or something like that when it gets to me, or I use the old "Dont get mad, get even" and just ranger up and blast them to bits with 4 shots. But its still annyoing that they havent bothered checking the 1887's out, cause they clearly cannot be ment to be able to shoot that far when all other shotguns have shells that just vanishes in thin air unless the person you are shooting is atleast 2m infront of you.

The Javelin glitch....FOR THE LOSS.

It's funny this thread is here, because lately I've been finding that when I am done playing I am more annoyed that in a "well that was fun" feeling.  It's not even that I'm losing, I'm still basically always in the top 3. It's just not fun anymore. 
 
Snipers with auto-shottys, grenade launcher spamming, sprinter knifers, dual 1887s, things happening that totally shouldnt' be  due to crappy P2P, Painkiller induced immortals. Every single game has at least one of these, and got damnit. Ugh.
 
It feels like they tried to cater to basically every player and every playstyle and made a game that just doesn't flow.