My brother Josh is a very talented concept artist. He has worked on many highly rated video games (Halo 4, Call of Duty Black Ops, etc...) and also done freelance for TV/movies. He has recently posted on his blog of a small portion of what he had done for Halo 4. Halo is a multi-billion dollar video game franchise owned by Microsoft Studios.
Click on the link to see the rest on his blog. He will be uploading more in the future.