The painted covers for Dell/Gold Key titles were often outstanding, especially because most comic covers at the time weren’t painted. As a kid, I loved Turok, Son of Stone (dinosaurs, cavemen, and American Indians. And tell me – what other title treated American Indian characters as not only the heroes, but made them completely sympathetic and competent Good Guys? Frontier and Western comics like DC’s Tomahawk sometimes gave them their due, but they were generally antagonists, and outfought and out-thought by the White heroes)
I also liked the Magnus, Robot Fighter covers. The science fiction was a bit out of date by then, but the covers were masterpieces of nostalgia, even then.
I wasn’t a fan of the rebooted series many years later. Or of their covers.
They covers aren’t in the same class, but I do like them and the series itself – Phil Foglio’s 4-issue run of Angel and the Ape from the 1990s