Groovy, baby.

No genre of music walks the line between greatness and stupidity as often and as gracefully as psychedelic music, and nowhere is that more apparent than in the artwork that often accompanies the albums. Some of it is great, some of it is terrible, and all of it is pretty ridiculous on some level. So without judging the merits of the music contained within these records, here are the 10 albums I feel most embody the precarious balance between mind-expanding mysticism and silly cliches found in most psychedelic music. I still don't know what exactly that is, but usually some combination of garish color, barely legible text, and deliberate non-sequiturs which may or may not symbolize something will do. Without further adieu:

Tom's Top Ten Most Psychedelic Album Covers:

1. The Beatles - Sgt. Pepper's Lonely Hearts Club Band - I said I wouldn't judge this based on the music, and I'm sticking by that. But the famous cover to this album is great for some of the exact same reasons that the Beatles were great: it takes a previously existing aesthetic and solidifies it, redefines it, and makes it 1,000 times better than it ever was before all at the same time.
2. The Incredible String Band - 5000 Spirits or the Layers of the Onion - Night and day, alpha and omega, yin and yang, the entire earth at the center, and... yup, there's an onion at the bottom.
3. The Zombies - Odessey and Oracle - Note that I didn't misspell "odyssey," the Zombies did. I have to think that sales of any fabric with a paisley pattern shot up about 1000% in England during the late 1960s.
4. The Dukes of Stratosphear - 25 O'Clock - For those not in the know, the Dukes of Stratosphear were actually XTC in disguise, so this isn't so much the genuine article as an homage of sorts, with the benefit of 20 years of hindsight and far lower levels of LSD. Like all good parodies (and like the music contained within), it's done with no small amount of affection and sincerity.
5. Cream - Disraeli Gears - Of all the records from the late 60's on this list, none were more obviously meant to be viewed not on a 5" CD cover (that obviously being nonexistent at the time), but a 12" LP cover, mainly due to the fact that there is as much crap crammed onto that as can possibly fit without needing a microscope to see them all. I want to say "everything but the kitchen sink," but I'm sure the kitchen sink is somewhere on there. To think that Eric Clapton, faux-blues-traditionalist, was a mere couple years in the past (and a couple years in the future) when this was made...
6. The West Coast Pop Art Experimental Band - Part One - I really can't make heads or tails of this one. Were they trying to suggest that their album was recorded inside a giant kidney?
7. The Strawberry Alarm Clock - Wake Up... It's Tomorrow - These guys single-handedly ruined this entire genre for everybody. In a post-"Incense and Peppermints" world, how could anybody possibly take the idea of psychedelia seriously? Everything about the Strawberry Alarm Clock embodies some cliche or stereotype about psychedelic music. This garish nightmare of a cover must have been a sight to behold in full LP size.
8. XTC - Oranges and Lemons - XTC have the distinction of making this list twice, with two different names. Again, this is more of a knowing wink than the real deal, but still, how could I not include an album cover that has a guitar with a horn on the end that's spewing out bubbles? Or something like that. The other guitar appears to have a headstock that turns into a rocket ship.
9. Todd Rundgren - A Wizard, A True Star - I have this one in its original 12" LP format, and I have to hold it at arm's length to look at it. Notice that Todd's left eye is surrounded by an ear... and also that it is bleeding. I think. This is 60s psychedelia filtered through a 70s coke binge.
10. The Jimi Hendrix Experience - Axis: Bold As Love - Nobody in the late 60s was as brazen with their faux-Indian-mysticism as the Experience were here.

Honorable mentions:
Pink Floyd - The Piper at the Gates of Dawn - Part 2 of the paisley revolution.
Donovan - Sunshine Superman - The perfect embodiment of Donovan's foppish and oh-so-British version of psychedelic folk-pop. I'm just mad about Saffron...
The Beach Boys - Friends - In the late 60s after Brian Wilson crashed and burned with the failure of Smile, the Beach Boys apparently decided to get together in Brian's room, smoke a whole bunch of pot, and talk about how much they like each other. And this album popped out. It's actually pretty good.

So that's that. Feel free to suggest examples I may have missed.