What kind of player type do you hate most?

Probably people that just camp around and do nothing. Essentially, those types of players stall whatever game for as long as they can, even if they know they'll lose.

 

Sometimes you have the option to block them (depends on if the game has the option), so they won't appear in your later matches, so it's not really the biggest issue. But I generally think it's better to play with people you know rather than play with strangers, just because it's more reliability than playing with strangers. You never know what to expect from players that you play with.