I had one player in my last campaign I could go on all day about. He just had no common sense, and frequently circumvented the rules until he got caught.
So much worse than that, though, was the Warlock who joined my campaign for just a few games. He decided he wanted to be evil, and he wanted to have undead minions. While I had no problem with this, the rest of the party and I expected him to roll-play in order to be accepted in the party instead of them just letting this evil undead-spawning guy they've hardly met in their group. So he threw some concealing robes on his minions and a game or two later they went to the astral plane and the undead, being mindless, couldn't move. So he puts them into his bag of holding and the party just stares.(Bags of holding, as I'm sure I don't need to mention, have a limited supply of air and are generally not comfortable to travel in when filled with goods.) The party mage asked him, in-character, "What are you doing there?" to which he sullenly replied out of character "Does it really matter?" Gah. No one really wanted to throw out their entire suspension of disbelief for the guy, and I remember him leaving the group shortly after.
In short, I'd much rather have a player who role plays poorly then one who refuses to role play at all.
Captcha: face the music