I am a huge fan of Michael Ostermann's digital art illustrations. Each one sucks you into a surreal alternate world. Here is how he describes his process:
"Every project is different; in both needs and approach, he usually likes to start with a good photograph, a good idea that sets the mood of the overall image. He then applies his self-made resources and uses several photo-manipulation techniques, seeing where it leads."
Check out his Blog, Portfolio, and Twitter account to keep up with his amazing work.