Lots of good music in this thread. You guys who like DJ Shadow might like RJD2 as well.

Many of those I like the best have already been mentioned but I'll just repeat them to put emphasis on them.

M83
65daysofstatic
Explosions in the sky
Boards of Canada
No need to describe these, as they have already been described.

For some unmentioned stuff, I'll recommend the following, but I'm not very good with specific sub-genres so don't go bananas if I got it wrong

Crime in Choir - Alternative rock with some saxophone stuff, sounds cool.

Vangelis - Mostly slow-tempo synthesizer music. Very relaxing, and it often makes me drift away~

Futuristic Sex Robots - Nerd rappers rapping about nerd stuff. I find them amusing, and their album isn't bad, considering it isn't done in a professional studio. They also release their music for free on their web site. Contains explicit lyrics though, so be warned.

Machinae Supermacy - Swedish prog. metal with "chiptunes". The lyrics are often about video game stuff, but sometimes include pop culture references, like from Aliens or the Matrix. A lot of their music is also downloadable from their web site.