Digital painting and drawing. I'm already not bad at that, but I want my skills to be semi-professional at least. I have a very vivid imagination, and I want to be able to recreate the concept I see in my mind.
Computer science foundation. Right now, I'm at the stage that I know enough to explain them in layman terms, but not enough to actually participate in an active discussion or projects that rely heavily on academic knowledge. Stuff like compilers and interpreters, computer architecture, database systems, distributed systems, and OS architecture.
Another item on my list is reflecting more about philosophical and psychological matters (I read more fiction books than non-fiction ones at a ratio of 25:1, the only bibliography I've read was about George Lucas).