I can't believe nobody has mentioned Moby or Underworld!
Yello is awesome, they provide so much to the listening experience.
Some others, most have already been mentioned:
Daft Punk, Air, Mark Farina, Crystal Method, The Orb, Supreme Beings of Leisure, Prodigy, Thievery Corporaton, Propellorheads, Baldwin Brothers, and Richie Hawtin who also has albums under the moniker Plastikman
I like the Mr. Oizo recommendation, his experimentation with vinyl is off the wall and in the right state of mind...off the hook.
Also, some progressive rock bands which I recommend: Pan American, Trans Am, Tortoise, Ui