Which RPG have you played most in your life?
It would have to be the Hero System. When I first came to the Bay Area we played the living heck out of that system – Champions, Achaean Hero, Justice Inc., Fantasy Hero, Danger International, Star Hero – it was our go-to system for almost everything.
Of course, this was back in the old days (the old days – yesss) before anyone ever had the idea of “hey, lets publish a master rulebook and then a whole bunch of setting books to go with it!” so none of the games were 100% compatible with one another. But we had great fun. I still have fond memories of my JI character, “Wombat” Dundee, Alan Hicks my Star Hero character who spent three entire sessions lying in an autodoc (ok, not such a good memory), or my Achaean Hero character Nineus of Crete, a great hero who carried his nagging crone mother on his back everywhere he went.