How's this for cool? A DJ spliced together The Beatles' Paperback Writer and The Monkees' I'm a Believer into one fairly coherent song/video, Paperback Believer.

He's given the same treatment to many other songs at his website (no video that I can find, though). I was also pretty impressed with Rapture Riders, a mix of Blondie and The Doors. This one still has too much Madonna for my taste...

Thanks to NightBazaar at Macca4Ever!