You mean in terms of physical appearance? Because the #1 turnoff for me in a girl is definitely if she acts all boujie and whatnot. That sickens me to the fullest.
But in terms of looks, there's not much that turns me off other than weight and yes hair. Yes, I kno, its bad. But I'm not saying a girl isn't pretty because she is chunky or hairy, I just end up thinking that she is lazy and doesn't work out or doesn't care about her looks (or just doesn't KNOW how to look nice). Because I'm a rather athletic person and enjoy working out, I like someone that feels the same way and has that reflected in their physique. If I see a girl with hairy arms or legs (yick), I sort of feel sorry for her sometimes because of that little thing that will turn guys off like myself. I try to get over those things tho and get to know them before I make a solid conclusion.
However, as soon as I find out a girl plays the same video games I do, all turn offs are turned ON and she get a bragillion hot points :)
Materialism. Umpa lumpa skin. Peroxide hair. Too much make-up. Trashy dialect. Dialect that suggests a low level of intelligence. A low level of intelligence. Knowing who the likes of Jordan and Justin Bieber and Robert Pattinson are but not knowing anything of, or caring to learn about, the likes of MLK, JFK and Winston Churchill. Girls who aren't interested in the history of the world, and the real world in which we live. So girls who are ignorant and just think about music and parties all the time. You can't have a good conversation with them. This is probably why I don't talk to girls much. Because pretty much every girl I know sadly only wants to talk about The Hills and *Insert Paparazzi Paradise magazine here* (I actually can't recall the name of one because I don't care... but then, Paparazzi Paradise magazines don't deserve any such kind of recognition).
if they have the wrong personality. like they're stuck up or just plain mean/bitchy. or if she's needy/clingy. like she can't live life unless she has a boyfriend. and then there is slutiness. you can be sexy but not slutty. there is a big difference. I might fool around with a slutty girl but I'm never gonna take her serious. in most cases I won't even bother with the slutty girl cause its just not worth it. and last but not least, dumb girls. airheads are totally unattractive personally.
For me, I hate shallow, slutty girls. They just come off bad girlfriend material. Fun, natural girls, mixed with decent hair and a decent body is generally a better combination than a super hot airhead whore.