Several music websites have joined together to put out an interesting list of 15 Mash-Ups You Need to Hear. 

The collection appears on Loudwire.com, UltimateClassicRock.com and Diffuser.fm.

They aren't exactly NEW, so you may have heard some of them before. Regardless, here are a few of my favorites:

Nirvana's "Smells Like Teen Spirit" with The Jackson Five's version of "Rockin' Robin".  (Audio)

Justin Bieber's "Baby" with Slipknot's "Psychosocial".  (Audio)

Blondie's "Rapture" with The Doors' "Riders on the Storm".  (Audio)

The Bee Gees' "Stayin' Alive" with "Another Brick in the Wall (Part 2)" by Pink Floyd.  (Audio)

The Eurythmics' "Sweet Dreams" with The White Stripes' "Seven Nation Army".  (Audio)

You can browse through a slideshow of all of them, beginning at Loudwire.com.  It will automatically take you to the other sites as you click forward.