Firstly, some English electronica duo called AUTECHRE who make crazy music which, being limited in taste as I am, I can only really liken to mainstream digital maestro Aphex Twin. It's all clicks and beeps, basically.
I got shown the video below by my friend's brother, who is an enthusiast for this sort of music. He found out about the band in a magazine which showed screenshots of the programs used to create this sort of thing, which are just overwhelming - they look more like math programs or even puzzle games than something akin to GarageBand or Reason. As such, the music is incredibly complex in terms of timing (although I'm not one to say it's all planned with any exactitude - I imagine this is the sort of music which sort of happens by itself half the time), and the visual accompaniment is accordingly crazy. It's animated in a 3-D program by a fella called Alex Rutterford, who apparently took inspiration from a (probably pretty frightening) acid trip. The song's quite famous and is called Gantz Graf.
It really reminds me of Rez, a 2001 PS2 game in which the player flies through a virtual world destroying virtual bad guys with virtual lasers and making lots of beeps and crashes as a result, which is supposed to be musical. It's a great deal of fun. Below is an example of some of the more interesting action you're likely to get treated to in the course of the game.
The video for the Beck song E-Pro takes a lot from this game, but I don't think I can embed it because the music industry in England is pretty shit right now, not letting Youtube show us music videos and whatnot. See if you can find the video, though, it's pretty cool.