I don't know where to begin... at least these should be pretty easy to find:
Boards of Canada is one of my favorite groups, full-stop. Seek out everything, but most importantly Geogaddi and Music Has the Right to Children.
Early Prefuse 73 is fantastic, especially his first two albums, Vocal Studies + Uprock Narratives and One Word Extinguisher. If you can, seek out Scott Herren's releases under other monikers such as Delarosa & Asora, Savath & Savalas, etc.
Flying Lotus has really impressed me lately, his latest album Los Angeles sounds a lot like Prefuse's earlier stuff.
Aphex Twin (Richard D. James) is not for everyone, but he's made so much varied music over the years you're bound to find something you like. I suggest the Selected Ambient Works compilations, and I Care Because You Do.
The German label Kompakt is indeed great, as Gibby noted. For a summary of what they're about (minimal tech-house, mostly), check out the Total series. They also have a great ambient series out called Pop Ambient.
For more militant techno, look no further than Underground Resistance, which is a label, movement, and more rolled into one entity. Acts include Drexciya, DJ Rolando, Galaxy 2 Galaxy, and all their various aliases. It's deep and messy and mostly available on vinyl, but they do have a few compilations out.
Akufen produces fantastic, chopped-up tech-house. Look up the album My Way.
More on the ambient side of things: Christ. Look up Metamorphic Reproduction Miracle.
It's such a large spectrum of music that it's actually hard to recommend stuff, but check back here and tell us what you like of what you've been recommended so far, and I can give you more recos in either direction (more to the soulful side of things, more hardcore tech stuff, breakbeat influence, house-y, etc).
