Lots of great ones already. Here are my favorites:
Aphex Twin
Amon Tobin
Squarepusher
Boards of Canada
Mouse on Mars
Autechre
Favorite albums:
Aphex Twin: I Care Because You Do, Selected Ambient Works Vol II
Amon Tobin: Permutation, Supermodified
Squarepusher: Budakhan Mindphone, Hard Normal Daddy
Boards of Canada: Music Has the Right to Children
Mouse on Mars: Glam
Autechre: Tri Repetae++
Some favorite tracks:
http://www.youtube.com/watch?v=mUT3KoxVzQg Aphex Twin - Alberto Balsalm
http://www.youtube.com/watch?v=FATTzbm78cc Aphex Twin - Window Licker... ah yeah...
http://www.youtube.com/watch?v=oz3PP...eature=related Aphex Twin - On
http://www.youtube.com/watch?v=i524g...eature=related Aphex Twin - Cliffs... gotta be in the right mood for this one
http://www.youtube.com/watch?v=wTL0t_HHkZI Amon Tobin - Nightlife
http://www.youtube.com/watch?v=K1RzfzIOC-E Amon Tobin - Sordid
http://www.youtube.com/watch?v=eicM0TSEZrU Amon Tobin - People Like Frank
http://www.youtube.com/watch?v=ZHy_XONbU3o Squarepusher - Iambic 5 Poetry... listen at least 3 mins trust me
http://www.youtube.com/watch?v=79SN8I9Fw8M Boards of Canada - Turquoise Hexagon Sun
http://www.youtube.com/watch?v=F9JI-N4ltR0 Mouse on Mars - Mood Leck Backlash
http://www.youtube.com/watch?v=60bZzyrzCks Autechre - Dael
http://www.youtube.com/watch?v=aFD2O8Vn6K4 Autechre - Second Peng