Hardcore nerding out. Chilling with mates. Occasionally working out. Movies. Out randomly walking around. Shopping. Everything girls do, really. Haha. I'm just one type of guy though. I can't speak for all of us.
I'm a workaholic, so a lot of my free time goes to cleaning and maintaining my equipment, staying in shape, or reading work-related articles and literature. The rest of the time I just take down time doing small, lazy things like watching the telly or going for a walk.
hanging out with friends or family when I can, playing computer games and watching TV/ movies when I can't. occasionally I'll go out and sing karaoke with or without friends. the rest of the time I'm working, exercising or cleaning.
When I'm not working, in school/doing homework, or in the gym I spend my free time- with friends, reading (mostly online articles and stuff), listening/finding new music, trying to find time to pick up my guitar and practice, and whatever else I can find to do.