If you enjoy some of the glitch or IDM suggested in this thread, check out Wee DJs. Lots of free and cheap tracks at his site:
http://www.thismachineisbroken.co.uk/
I really like his Fear and Lothian LP. He was operating under the Touchin Bass label for years - they have other good stuff in the dark/glitch/electro sub-genres if you're interested. I have most of the vinyl that the Touchin Bass label produced.
More mainstream, I also enjoy Ladytron and Crystal Castles. For the latter, more their first album than their latest stuff.