You should check out:
Kruder & Dorfmeister (sort of the great grandfathers of the genre)
Tosca (which is a side project of Dorfmeister's)
Nightmares on Wax
David Holmes
Craig Armstrong
Fila Brazilia
Autechre
Morcheeba (crossover downtempo/trip-hop)
Hit
http://www.allmusic.com for more. Great site.