Two of my favorite artists are John Howe and Alan Lee. (I know we are only supposed to write about 1 artist, but these two go hand in hand.) They are concept artists that have been drawing scenes from J.R.R. Tolkien's work for years. They both worked on the design of the sets, costumes, and creatures for the Lord of the Rings movie series.
Alan Lee's work ( http://fan.theonering.net/middleearthtours/lee1.html ) is usually in watercolor. His scenes are beautiful, graceful and often haunting.
John Howe's work ( http://fan.theonering.net/middleearthtours/howe3.html ) is much crisper and more action oriented than Lee's.
Both of these artist would have to be in my list of favorites because their art is based on a story. Their pieces often depict an epic or heroic scene which I admire, and I hope that my work will take inspiration from their own amazing pieces.