First off, anything by The Avalanches.
Since I Left You and
Frontier Psychiatrist are too damn good. Plus, their music is made entirely of clipping together something like 3000 different vinyl albums, and altering each sound to fit what they need. Brilliant stuff.
Royksopp is great for just about anything. Songs like
Poor Leno,
What Else Is There,
Happy Up Here, and
Royksopp Forever all have a solid gaming groove.
And of course, Gorillaz.
Stylo,
Dare (Junior Sanchez Remix),
Doncamatic, and
El Manana, all fantastic pieces of music.
Lastly, I'd be remiss to leave out one of my favorites, Massive Attack, with
Unfinished Sympathy,
Protection,
Dissolved Girl, and
Safe from Harm.