I realized I never really made a list:
Classic:
John Byrne (obvs.)
Art Adams
Paul Smith
Bill Sienkiewicz
Alan Davis
Chris Bachalo (1994-2011)
Modern:
Phil Jimenez
Salvador Larroca
Kaare Andrews
Jerome Opena
Emanuela Lupacchino
Phil Noto
Frazer Irving
Carlos Pacheco
Olivier Coipel