I like Ditko but I dunno....I'm more a Kirby fan. Ross Andru is real good in action sequences but sometimes his perspective is off. Alex Ross is a fantastic painter/artist but just "good" with the expression of emotions in action scenes. I dunno they look beautiful and all, but never feels intense or that the stakes are high. I forgot about Steranko and Dick Dillin. Norm Breyfogle is a marvelous Batman painter. Herb Trimpe and Sal Buscema are legends with Hulk and Keith Pollard was amazing with Thor. If you've seen the work of MarshallRogers, I think he influenced MacFarlane a lot.

I guess I have a lot more names if we're talking about skill in art--but with actual comic breakdowns, those names are my faves.  

I actually had a lot more names that popped in my head last night--arrgghhh!!