My list of peeves could go on and on.

-Dry pot bluffers, in tourneys. Ring games I see no problem.
-rabbit hunters
-people who whine about AA "always" losing etc.
-people who say "alright, gimme some pocket aces" before every other hand
-people who say "you got Ace-Jack?" if you bet when the board is KQT. Or they say "you got 67?" if the board is 458. Or whatever.
-People who give you perfectly good pot odds to draw and then can't believe you "sucked out" on them, or "rivered" them

But the number one Patented Pet Peeve o' LeFou for all time:
-People who bust me in the Gauntlet !!!!!!!!!