Bad hygiene, guys who are too 'vanilla' and afraid to try anything new sexually, submissiveness in men, guys who drink heavily and often, and guys who don't want a committment and a future.
I wasn't always this way, obviously there have been times when a guy chasing a relationship was a turn off, and times when I drank heavily so a guy drinker wouldn't bother me. But yeah that's my current list.
Edit: Ooh how could I forget? Guys who ain't into music, who say they LOVE music and it's their life, but in reality just listen to whatever's on the radio or in the charts. I don't have a problem with a partner being massively into a different genre of music than me or disliking much of the stuff I listen to, but a lack of passion for music means we're just never gonna get it on long term. I've dated musicians exclusively apart from one person.