I think the newest (as in most recently added) would be all the songs on this CD of songs from the T.V. series The Sopranos (I was mainly looking for the theme "Woke up This Morning" but the other songs are great too.)
Garbage- I Think I'm Paraniod
Gwen Stefani- Hollaback Girl
Madonna- 4 Minutes
Collective Soul- December
House Of Pain- Jump Around
MARRS- Pump Up The Volume
Black Eyed Peas- Let's Get It Started
Linkin Park- In The End
Eminem- The Real Slim Shadey
Bear McCreary- All Along The Watchtower
Pet Shop Boys- West End Girls