Autechre makes great thinking music.

Conversely, it also makes great music to trip out to (not that I do drugs or anything; why would I need drugs when I have this?). My favorite tracks for so far are Pen Expers, Eutow, and Gantz Graf. But I only have 3 outta their 24 albums right now, so there's probably others I'd really like too. 

But when all of this complex, partially computer-algorithm-generated (except for Eutow) music, I listen to some simpler stuff too. Souleye's soundtrack to the game VVVVVV, is really catchy. I encourage you to download it from his website. When I want something more brightly colored, I go for Anamanaguchi. Seriously, it makes you feel so much better after listening to them. 

Oh, I almost forgot about Clipper. That's another Autechre song I like, and it's not computer generated like Gantz Graf and Pen Expers.