Here are some more fantasy artists to be aware of.
Luis Royo does some incredible fantasy and SF covers. He has a way of portraying movement in stationary subjects. Please be aware that his site has a lot of adult content.
An old favourite, who still brings out fantastic artwork is Jody Lee (perhaps best known for her work on Mercedes Lackey's Valdemar books).
An artist I only became aware of recently, with his cover for Brandon Sanderson's Warbreaker, Dan Dos Santos is currently on the ballet for the 2009 Chelsea Awards for best cover illustration: paperback book, for Patricia Briggs's Cry Wolf.
And finally for today, Chris McGrath, who did Rob Thurman's Nightlife, Butcher's Dresden books and more. Here's the cover for Matt Sturges's Midwinter.