Wow, that's almost as twisted as Pat Boone's In a Metal Mood: No More Mr. Nice Guy. He's got a great cover of Metallica's Enter Sandman among others. Amazon was also nice enough to point out Lounge Against the Machine, but the sound clips there don't excite me too much. If you're into genre bending, one of my all-time favorites is The Moog Cookbook. For something really warped, it doesn't get much weirder than Senor Coconut's Latin rhythm take on Kraftwerk, El Baile Aleman.