I don't have any favorite digital artist. I think there's hundreds of very good artists who bring interesting different styles.
Here's another one... good descriptions of his work... making also some 3D models. I especially like his "Chicago Flood"...
http://www.herbrich.com/index.html

Wow! He certainly is prolific. I love the seahorse taking a bath in the shell. Very cool stuff!

My all time fav artist has got to be damnengine. If you havent heard of him yet then I suggest you at least have a look now.
http://damnengine.deviantart.com/
http://www.damnengine.net

My all time hero for sure.