Computing - Obviously :-D
Retro Gaming - Computer and console. I have a collection of over 150 NES and SNES game carts. And a few others. Sega, Atari, C64, N64...
Music - played guitar since 1987, studied at a music school for 2 years '91/'92 then worked around the city (Perth) in bands for 10 years before quitting to follow computer studies. It's just a hobby now.
Art - I like to sketch. Pencil mostly. I'm no damn good at it, but I enjoy it.
I'm sure there's more, but these are the main ones I guess. On any given day, one may be more prominent than the others.