I don't particularly like the TF2 community, to them a great hat makes a great player. Although I blame Valve more than the community there.
If you play Left 4 Dead a lot you'll find there's some great people there. It's a good idea to find people to play with, of which there's plenty since pub players tend to ragequit.
Black Ops' community is unfortunately not that great. I personally blame Modern Warfare 2 for the attitude, because every good player in Black Ops is often accused of hacking. And the server admins condone it, which annoys me. If I was an Admin I'd kick people for accusing of hacking with no evidence. There's a handy thing called theater mode, before you accuse someone of using an aim bot check there. Other than that, no one really uses their microphones which kind of sucks as well.
Bad Company 2's community was alright last I played. But to be honest I haven't played since May.
And of course the console community is the worst, most of those playing haven't reached puberty.