Umm well the list would be too long if I would list all good electronic artists.
I like a bunch of different artists in different electronic genres.
Not that much into dance/trance/house.
But here's some sort of a list... Basicly artists that i've listened to the most in the last year or so.
ambient/chillout/trip-hop/downtempo:
Thievery Corporation
Boards of Canada
Massive Attack
Air
Amon Tobin (also his older releases under the alias Cujo)
Sneaker Pimps
Slowhill
Rinneradio
múm
Sigur Rós
Arovane
Tortoise
Vangelis (nice movie scores)
idm/experimental/breakcore:
Aphex Twin, AFX (also other aliases used by Richard D. James)
Plaid
Wagon Christ
Luke Vibert
Venetian Snares
µ-Ziq
Kid Spatula
Squarepusher
psy/goa:
Shpongle
Infected Mushroom
Ott
Juno Reactor
other electronic artists (all sort of techno/breakbeat/alternative stuff):
The Prodigy
Orbital
Delerium
Cylob
RJD2
Moloko
Moby
The Chemical Brothers
Röyksopp
Apollo 440
M83
Daft Punk
Vitalic
Westbam (older stuff from before 1998 or so, good techno)
Overseer
Fluke
Hardknox
Umek
Fatboy Slim
The Future Sound of London
Prefuse 73
RMB
Dune (very good if you like happy hardcore/rave stuff)
Leftfield
Underworld
Anthony Rother
Big enough list for ya?

Should keep you busy for a while if you decide to give them all a listen.
You should really try last.fm for finding artists.
I found like 1/3 of these artists through there.