Both? Honestly I'm an intellectual guy and I REALLY appreciate a girl with a good head on her shoulders but I'll be honest, I couldn't go for a girl I had no physical attraction to. That doesn't mean she has to be a super model but if she doesn't do it for me a romantic relationship isn't going to happen. Fortunately most girls are a pleasant mix of both.
There has to be some level of both. If she's the hottest girl in the world but is mentally challenged it would feel a little weird having sex with her, Dah Dah Dah where is my helmet. If she is really smart but looks like a man then how would you know she was a woman. Hahaha. Stop the extremism, most girls have a good deal of both. So long as she is attractive enough to me to have sex with then I would chose brains after that barrier has been crossed. A girl that can stimulate my brain, keep me interested in her, enjoy things with me, has the brains to be successful in life, could raise children to be smart if it got to that is more important. A hot body fades with time, a pretty face sticks around for a while, a personality and intelligence is for life.