Fantastic Universe
69 issues ~ June-July/1953 - March/1960
(All digest sized except the last 6 are pulp size)
Here's the lion's share of the covers!

Cover art by Alex Schomburg, Kelly Freas, Mel Hunter,
Ed Emshwiller, Hannes Bok, Virgil Finlay & Norman Siegel
(Finlay's 20 covers from March/57- Oct/58 is his longest
continuous run of covers on any magazine!)

Fantastic Universe didn't contain interior illustrations until
changing it's format for the last six issues. Here's all of Virgil Finlay's
interior illustrations for the Oct/1959 - March/1960 issues!