DC
Batman (all of them, but particularly Frank Miller and Neal Adams)
Kirby's 4th world (New Gods, Mr. Miracle, Forever People, Jimmy Olsen)
Justice League (particularly the first 200 issues)
Watchmen
The first three years of New Teen Titans by Wolfman/Perez
The Legion of Super-heroes, particulary the Great Darkness
Catwoman
Green Lantern/Green Arrow, particularly Neal Adams
Supergirl, Lois Lane, and Wonder Woman in the 1970's
Kingdom Come, the art was awesome
Marvel
Fantastic Four ... Sub-mariner and Dr. Doom
Thor, anytime Loki, Hercules, or other immortals are around
Captain America (all, but particularly Kirby and Mark Gruenwald)
Daredevil
Amazing Spiderman
The Bryne/Claremont Uncanny X-Men Run