That's going to be difficult as I've played in a LOT of hybrid games. The first big campaign I was in was a D&D/AD&D rules hybrid- the best part of which was we'd somehow reduced spellcasting to a %ile ability- which gradually evolved into an amalgam of ideas taken from, let's see, the Gamma World box set, the Dragonlance rulebook, and Stormbringer.
Regular "by the book" AD&D was kinda boring after that.
Stormbringer was fun as was the Top Secret game I was in.
Then there were the GURPS games. Alas I can't even begin to guess what rulebooks were involved in those. All I know for sure was I had a character sheet. These, and a GURPS Mekton (?) game, were primarily one-shots. Actually a LOT of the games I played in were one-shots.
Doubt I could remember them all. I do vaguely recall creating characters for Palladium's (?) Robotech and Teenage Mutant Ninja Turtles games.
Played, or tried to, a lot of Avalon Hill stuff. Ran quite a few games over the years, mostly D&D/AD&D (Dragonlance, Spelljammer, et al) and Stormbringer with the occassional game you've probably never heard of like Skull & Crossbones. Also got some good use out of my MERP and Lords of Creation material, though I never really ran the games "out of the box".