I think if you're putting on so much makeup to the point where you look completely different when you're not wearing makeup, then that's not so good. I wear makeup, but I try to make it look as natural as possible, I always look the same with or without makeup, but I just feel better about myself if I wear it.
I prefer little to no makeup. Lots of makeup can make a chick look FUBAR. Case in point: paris hilton is gross most of the time... but when she came out of prison without any make up and without the whole $2 streetwalker look, she was quite attractive.