Stephanie Law for beautiful angels and birds in a fantasy vein. She inspired 2 of my tattoos.
http://www.shadowscapes.com - also with lovely butterflies, which usually annoy me.
H. R. Giger for Mecha-Porn.
Brom for dark landscapes, strange people, and a nightmarish blend of fantasy-horror.
Michael Whelan for hardcare fantasy images.
Waterhouse for romantic fantasy images.
http://www.artmagick.com has some great themed galleries of you like turn-of-the-century art.
Mark Ryden at
http://www.markryden.com has some seriously creepy art that looks kiddie but is really about gore, paranoia and nightmares. My favorite piece here is "Angelica Carnis" - a beautiful angel holding a steak amidst other pictures of meat.
Lucifer.