We can't get enough of the My Favorite Album Artwork blog. It's absolutely mind-blowing. Some of the stuff on there is totally, wonderfully ridiculous.
The blog also has links to where you can hear the music contained therein (usually CD Baby). It's a treasure trove of good, weird, bad, wtf, shit, huh, and ohmygodaweszomesss!
Check it out. Make sure you have some spare time handy, 'cause you'll get hooked.