Having an artist as my ex-girlfriend provides an odd bit of perspective here.
You can really divide the fan faves into two groups: Comics-esque, and Classical.
Comics-esque artists include folks like Wayne Reynolds, Danilo Moretti, and Erol Otus who have very stylized pieces. They tend to go in for pen and inks a lot, with limited lines used to perfection to suggest shapes and perspective.
Classical artists include the real classics of AD&D, like Easley and Elmore, and the more modern masters like Todd Lockwood. They go in for pencils and oils mostly, it seems, and my artists friend refers to them affectionately as 'render monkeys' because they go for photo-realism a lot, and have a lot of precise details. She is horribly jealous of them, because everyone seems to love the detail-heavy style, and she goes more in for the Comics style, particularly a la Terry Moore.
http://www.strangersinparadise.com/gallery.html
I personally go in for the stranger sorts of styles that don't fit either category, like Tony DiTerlizzi, Rebecca Guay, and D. Alexander Gregory. I like my fantasy art more 'fantasy,' less 'Italian' or 'Spider-man.'
But if you want to ask who I think is the best fantasy artist right now, well, of course that's my dear friend Jessie-Lynn Jones, a bright star just waiting to be discovered.
Her own website
or
Her ENWorld Gallery