[jackaaron]

In No Limit tournaments (STT & MTT):

Playing way too many hands out of position.
Min-raising with great hands, and not understanding why people call their raise with a wide range, and stack them.
Not having the ability to ever understand how to get off TPWK.
In lower limits...attempting the call flop, call turn, reraise river bluff like their favorite pro with absolute air way too often.
Drawing to a flush no matter what the pot odds dictate.
Defying logic and betting small on big hands, and betting big on garbage hands way too often (it's good to mix things up, but bad players actually do the bet small with nuts/bet big with garbage way too often).
Not understanding how position can be to their advantage.
Not putting opponents on a range of hands.
Going nuts early in tourmanets to gain a big chips stack, then when they get it, tightening up later, and on the bubble.
Not having any understanding whatsoever of bubble play.
Showing hands way too often.
Emotions:
Taking other player's actions personally.
Wanting to "show" the bully of the table that they can't be pushed around.