When I play the music that I've purchased from iTunes in the order that I've purchased it, my iPod transitions from Barenaked Ladies singing a semi-acoustic remixed version of "One Week" to Michael Jackson's "Thriller".
Wonder what's next?
James Blunt's "Your Beautiful"
Not quite as startling as the previous transition, probably because of Vincent Price's voice over. ;-)
The point where it goes from Idina Menzel to Kelly Clarkson is a bit odd, too, though I love both songs. It's eclectic.