I still haven't done any GURPS. Back when my gaming group still existed in High School, we did AD&D 1st and 2nd edition, Mechwarrior, Shadowrun, and a few other things. In college we tried some Rifts. And more recently I've done some D&D 3.5 and 4 (btw, 4 sucks compared to 3.5. It's D&D redesigned by WoW players), and also some Deadlands. I recently got the rulebook for Torchbearer (made with a Kickstarter campaign), but haven't opened it yet.
And that's about my range of pen/paper RPGs.