I found here a list of the 10 biggest dating turn offs for women:
http://www.lovepanky.com/men/understand ... -for-womenBut personally, I get turned off easily when a guy rants about his life.
I once chatted with this Dutch guy online who kept talking about how he was bullied when he was in high school, children throwing bricks at him and all those stuff. Of course he got my pity and sympathy at first. I comforted him like there was no tomorrow, but after a few weeks I came to realize that his self pity makes him a loser.
I can't really say that "I won't date a loser" but I would say that I won't date a guy who sees himself as a loser because then I would see him too as a loser. BIG TURN OFF. So women are not the only ones who must know how to carry herself with confidence, it's a requirement for guys too!
Next is hygiene. A guy who picks on his nose in front of me, who farts 24/7, who smells like a caveman, and urgh! Bad breath! I don't know, smell is really just very important for me. I easily get attracted to a clean looking, good smelling guy.