Rubik's cubes. I can't get enough of them. I carry one with my most places now, works great to pass the time when waiting in line and such. I also like other twisty/permutation puzzles. I can only speed solve the Rubik's cube though, any other puzzle I do pretty slowly by comparison.

I'm also a PC/Console gamer, and have been since I was 5. Always loved em.

Programming, I usually have some side project going. 3D programming is probably my favourite.

Photography, but it's not too often that I see a shot I like.

Quantum mechanics, though it's not as much of a hobby, as I don't know the math behind it.