Music Challenge: Mash Ups

I have been putting together a giant summer playlist, which I am totally addicted to. It is a mix of last year's summer playlist, and a whole bunch of new songs that I can't stop listening to at the moment. The only thing that all of the tracks have in common is that they put me in the summer mindset in some way.  The thing is, I'm going a little bit mash-up crazy.

 I have a challenge for you guys: provide the soundtrack to my insanity by way of: 
Mash-Ups. "a song or composition created by blending two or more songs, usually by overlaying the vocal track of one song seamlessly over the music track of another." (thanks wikipedia.)


Give me your tired, your poor, your mash-ups! What is your favorite?

Here's what I am listening to at the moment: 
10 rad mashups

The best mash-ups I've heard have either Biggie or Daft Punk in them.
My favorite mash-up DJs are: Girl Talk (dancing in the Girl Talk crowd at Bamboozle was the highlight of the entire festival), Super Mash Bros., party Ben, and the awesome DJ Earworm.


Also:

Should I give the person who submits my favorite mash-up a prize? Should I have regular music challenges with prizes? Do you want more contests? Should I just shut up? (I'm not going to.)


xxxx