Getting stuck on the worst team ever. Then having your smarter teammates always leave (and you can't blame them for trying another server, but when they then join the much better team it's pretty fucking lame), so you're always shorthanded by one or two players in addition to having a team full of clueless idiots. Then you have 2 afk's, and of course they'll both have one of the limited class/weapons. And the other team is just giving you a 30 minute Oz-style prison rape, and you just can't leave because you hate just bailing when you're getting spanked, so you spend the entire map there and when it's finally over (complete with other team "GG!" and clapping themselves on the back because they somehow didn't notice the teams were 14-9 for about 5 minutes) you quit the game in a fury and it just ruins your mood.
Bah, I say bah.
Bah, I say bah.