Sensitivity. This is one of the things that is sexiest about a guy. Many guys aren't confident enough in their sexuality to show their feminine, sensitive side. But I like it. I love it, it's easier to trust someone when they are able to feel pain.
Humility. It's a huge turn off when someone acts as if they are above someone else. It doesn't make you a man to have control over your girlfriend. It's okay to be wrong about things and it's okay to not have all the power in the relationship.
A Care in the World. Please do not act like you don't give a sh*t about everything around you. This goes along with sensitivity. It is OKAY to show emotion, really, it is.
Fitted Clothes. If your boxers are showing...do.not.talk.to.me. Is that not uncomfortable anyway?
A Heart. Sometimes all it takes is a little "I'm sorry". Guys who don't admit when they are wrong get misunderstood. It's hard to admit when you are wrong and apologize but sometimes you just have to do it. For the relationship.
Common Sense. Don't cheat on your girlfriend/wife/significant other. Seriously, it's just wrong. Why on Earth would you think it was okay? P.S. Being drunk is not a good excuse.
Everything on this list. I can't think of anything else at the moment so if you're a guy and you are reading this, please take notes. Maybe it's not all girls that agree with me, but I'm sure a large majority of them do.
Oh and by the way, a nice, toned body never hurt anybody...