Never mind the fact that you're listening to James Taylor over an R&B beat that quickly fades into 50 Cent's "In the Club" — in the world of mash-ups, it's okay. Night Ripper by Girl Talk ($14) is the best mash-up album we've ever heard — by a lot. It takes elements from nearly every musical genre, from new to old, and mixes them up like never before. The result is an absolutely infectious mixture of music, pop culture, and art that begs to be discussed at a party or with a group of friends. Standout Tracks: "Hold Up," "Bounce That," "Warm It Up." [Thanks, Kian]