Bicycle riding: Road, MTB and BMX
Powerlifting
Trail running
Brazilian Jiu-jitsu / submission wrestling
Tinkering with old cars.
Hobby electronics / hanging out at the hackerspace messing with random projects. I started an effort to build a Z80 based 8-bit "retrocomputer" a while back.
Lately I've been picking at learning to play keyboard / piano.
I've also been dabbling in trying to learn to draw.
I also like to read a lot, both fiction and non-fiction.
And last but not least, going to heavy-metal concerts.