Gears 2 - I found myself hating the constant bitching of the opposition between rounds so much, combined with the elitism "you didn't use a shotgun? you're a noob!" so much so that I stopped playing online almost immediately.
Left 4 Dead - I'm seeing L4D come up alot, what the hell happened to it? It's been around a year since I played it (disc broke) but it used to be one of my favourite games, the community was good, people got along. You had some dicks who'd kick people for not knowing the maps but not many, 95% of the time it was a good fun evening, even with randoms. To see so many on here slating it now makes me wonder just how bad it has become.
BFBC2 - I don't see why so many complain about Snipers/campers. I usually play an engineer but if needs be I'll countersnipe, which can be really fun in itself. Surely guys who throw away choppers/tanks/drive off in a humvee without a gunner are more annoying as they are wasting what can be used as a really good asset. I've found you have to have several different mindsets when you play, either attacking or defending. I used to hate getting owned by Apaches for example, so I trained myself up on Anti Air guns so I could effectively combat them. I will say I stay away from the Forum community though. K/D ratio seems to be akin to dick size and everyone only cares about who is biggest.