I used to be really into European cars (03 GTI 20th Anniversary, 02 Audi TT) used to auto-X, go to the track etc.) but that was a big money suck when I got totaled by a drunk on the highway, so I gave it up.
My first love will always be aquarium fish (Freshwater, generally South American fish, plants etc). I've got about 1100 gallons of water in the basement. Breeding/ raising dwarf cichlids, tetras, catfsh....)
Pinball...I play several times a week at the local pinball bar, we do a league a few times a year as well.
Video games. My brother and I are selling all of our arcades for more pinballs. I have NES (top loader and regular) Genesis, SNES, 3D0, 64, Dreamcast, PS2, 360, Gamecube and a ton of games to go with them all.
I think, for me, pinball is more of an addiction than it is a hobby...Hell, I gave up drinking, but still go to the pinball bar several times a week. Gets me a lot more credits, that's for sure!
Adam