Hmm, that's tough. Because singers always look marginally better to me if I like their voices. A good voice can make an average-looking person attractive, I find... so maybe I should mention someone who's not a singer...er, can't think of any right now...
David Gilmour
Paul McCartney
Axl Rose
Jim Morrison
Paul Simonon
Robert Plant
I say David Gilmour destroys them all, due to the fact he can speak French and his smile kills me.