Ditko era Spiderman aside, my favourite Marvel character is definitely Lee and Jack Kirby's the Silver Surfer - probably the most beautiful and complex (for Marvel) super-heroes in the companies history.
He recieved a revamp in the 80s by the French artist Moebius which I always think is one of the best of the marvel 're-imaginings'.
God, I could waffle on about this kind of thing forever.