aw, that's cool too. Mine are a combination of things I love. I limit it to 4 pictures per category unless I particularly love that one thing. Now that the picture amount is growing though, I'm starting to add more. I have things like artists, anime shows, albums, cool scenic anime stuff, characters, and pictures of my dogs or friends.
I don't want my immediate family knowing about my otaku-ness, so animu stays off my desktop that lives in our front room :(