Album covers fascinate me. They give a somewhat a visual perspective of the music hidden within their gate folds. The ones I really enjoy are the illustrated artwork, especially the ones done by Roger Dean. His cosmic architectural landscape design adorns albums from Yes, Asia and Uriah Heep. The photo above is one my favorites from Roger Dean- Yes Tales from Topographic Oceans.
Not just only Roger Dean I like, there is the Stanley Mouse/Alton Kelly combo whom does the Journey album covers and the "story" they tell.
Then there is Frank Franzetta's work on the Molly Hatchet and Nazareth album covers. Very medieval-screams rock and roll....
The portraits of "life, death and afterlife" of Iron Maiden's mascot Eddie are done by Derek Riggs. Some of them shockingly gruesome... What the hell, it's only rock and roll!
Another one I like is the Grateful Dead's Blues for Allah album cover done by Philip Garris..
There many more I'd like to post, some other time maybe... So what is your favorite album cover?