Most women look better with a little makeup, but many overdo it way too much. Most guys are a little "prouder" being with a girl who looks good in public with makeup. And to some extent in private, also. But there are a lot of guys who feel pretty good being in private with a girl who is comfortable without makeup at least a good part of the time. It gives the guy a feeling like the girl is being more honest with him by trusting his opinion of her without makeup. And as much as most guys like seeing the girl with makeup, not wearing it (sometimes) gives him a chance to really see the girl he is interested in, and we like that.
Well, I don't have one but my ex-girlfriend did, but she didn't wear normal makeup. She only ever wore eyeliner, like, thick as f*** eyeliner, on the bottom eyelids. And I loved it, it was unique =] She put on other makeup occasionally, when we were gonna do something special, but I didn't really notice a difference. She mostly did it 'cos I did it, hahaha.