Tyrants charging around everywhere when it isn't necessary and TKing (NOTE: running away when badly hurt is understandable), just because they can't be bothered taking a few extra seconds to get where they are going
Goons pouncing everywhere... see above.
People who complain about blocking all the time and blame dretches whenever they get killed
People who scream "DRETCHES OFF THE FLOOR!!!!", when a) you are playing a level where the walls are full of fiddly detail that make wall-walking virtually impossible b) the shouter has forgetten that dretches have to come down off the walls to kill c) lots of newbies are playing, for whom "DRETCHES OFF THE FLOOR" means nothing. Explain to them politely that they can wall-crawl otherwise they block bigger aliens and get them killed (this works wonders for me) d) Treat dretches with some respect, they are just bigger aliens that haven't fed up yet... which brings me onto:
People counting kills over the win (side issue: Tremulous really should report the kills/deaths ratio rather than straight kills) -- so you get experienced tyrants chasing after unarmoured humans instead of leaving them for dretches to feed and becoming bigger aliens which can help them win, or Battlesuited humans with Lucis and flamers going after dretches just so they can brag at the end about their l33t kill number (perhaps kills should be weighted by how powerful the killed opponent is)... and in both case completely ignoring structures. Incidentally... you don't get much reward/respect (messages or points) for destroying structures, even though it is ABSOLUTELY vital to winning. Using up your credits to grenade all the alien tubes and eggs (which no-one else seems to bother with), gets you a big fat ZERO in respect compared to the battlesuited super-dude who slaughtered 100 dretches with his Luci.
People who complain about teamkills all the time when there is a narrow corridor full of slashing aliens and firing humans.
People who think Tyrants are, like, IT. Tyrants are a bulldozer... useful, but all the other aliens have their uses, and Tyrants are pretty weak in many ways. Don't TK other aliens assuming that the player isn't good enough to get the points to be a Tyrant.
People who refer to their teammates as retards, morons or idiots. It's a game. Show a little common decency. So what if you lose because your teams is a bit new. So what if your builder made a horrible mistake. Get over it. You lost a game, that's all. This is actually part of a bigger problem in which you get a poisonous atmosphere in public games and it encourages griefing and still more unpleasantness. This is a big problem on SST, where the admins don't stamp down on rudeness, and worse, actually behave like this themselves.
People who don't apologise when they accidently TK... doubly so if you happen to be a tyrant or goon.
Oh and finally... and experienced players who stand in doorways like dopes.
Poll