Beauty is always in the eye of the beholder. Looks and personality are probably the two main thins we look out for in a partner, but being intelligent, to me at least, is just as important - I couldn't bring myself to go out with some air-head, not for any amount of time anyway.
Of course there are the extremes: the stereotypical geek - spotty, with inch-thick glasses, etc. - and at the other end there are the bimbos (male too) who think looks, if they have them, are enough to get by, and that brains aren't a necessity. (Of course those are both huge generalisations and of course not always the case - it's more common opinion.) Those two examples are what a lot of people would find "turn offs" so you could almost argue that the extremes (inre brains) are turn offs and so brains aren't attractive. But of course thats utter nonsense. I think its a case of stereotypes that, in this case, aren't attractive qualities although in reality we do want to date intelligent people.
Overall brains are attractive - to me, anyway - it's the stereotypes we create that aren't. On the other hand if you don't have a massive IQ (not that I do) then someone with a lesser IQ would be equally attractive as a smart person. This brings me back to my very frist sentence: Beauty, in all it forms, are in the eye of the beholder; its all subjective.
P.s. Don't expect, if you quote me, to get a reply anytime soon as India hasn't got the wealth of internet connections that Western countries do. If you do want to quote this I will reply, it'll just take more time.