Intelligence, to me, is not an option; it is a requirement. I can’t imagine really wanting to, or even being able to, get intimate with a woman if I can’t engage with her on a higher level than “she has a nice butt.” They say the brain is the largest and most important sex organ, and I don’t disagree.
That doesn’t mean she has to be able to carry on an in-depth conversation on the theology of St. Augustine in Dante’s Inferno (although, that would be pretty hot), but there has to be something there. A bit of depth, a bit of imagination, a bit of something more than Paris Hilton.