Remember watching those kids tv shows where all the kids sent in their pictures of their favourite cartoons? Whilst that might be long gone, there's a whole scene of up and coming artists that use video games as an outlet.
We'd not usually post individual artwork, but this recent Samus piece that appeared via Digg is pretty damn impressive. Check out the full resolution version here.
If you've never really looked into this subject, you should really check out deviantART - there's a whole category dedicated to games.