Well, if it was the other way around I would say - in no particular order
Dune - Bill Sienkiewicz (post Moon Knight)
Blade Runner - The late, great Al Williamson
Alien - Walt Simonson (Pre- Thor)
M - Jon J Muth
Worst
Superman - The Quest for a Peace (You think they would be able to improve it...Oh, Curt and Bob what were you thinking...)
In terms of the films - there had been no true 'adapation' of any comic only interperations. Light weight efforts such as From Hell, V for Vendetta have only helped to create a mis-representation of work. In fact, damaging the works.
Prephaps the best is Superman the Movie simply because the comics we so direr the time.
Still, I await the Ambush bug film.
CHEEEEEEEEEEEEEEEEKS!
Nuff Said!