I write.
I read.
I research subjects that interest me (especially psychology, actually what led me to this site in the first place as I discovered the articles before the forums).
I tend to animals.
I play World of Warcraft... a lot lately. More when I'm in a depressive episode.
I play Pokemon sometimes, too.

Those are the only hobbies I can think of. I don't get out much as all those hobbies show. But I enjoy doing them and I suppose that's what matters most.