Larry Elmore, Thomas Canty, or the original artist for the Aria comic. Canty is my favorite artist, but his style would only work with certain characters.
My two favorites are without a doubt Richard Luschek (who is a buddy of mine) and Peter Berting (who has illustrated a lot of stuff for D&D). Both have exquisite styles and put great detail in their art. Just have a look at these examples by Richard: