RPGs I have played.

D&D, AD&D – Basic blue Box D&D started it all.

Metamorphosis Alpha, Gamma World. Hiero’s Journey was recommended reading for Gamma World. To me, reading it sounded like a script for what play transpired in a game session or sessions of Gamma World.

Star frontiers, Traveler.

Gang Busters, Top Secret

Villains and Vigilantes, Marvel Superheroes.

Boot Hill

Games we invented back in high school: Space Pirates and Scout. As I recall pirates was more about ship combat and getting the cargo off the target ship. Scout was role playing and small ship combat.
I once owned rules for Metamorphosis Alpha, Gamma World, Boot Hill,  Top Secret. I don’t recall if I had Star frontiers, or just played it.

I own Mega Traveler, but never played it. I got is so I could have an RPG without grief from my now ex.

I also once had a game about being a carton character, Toon. It was a simople booklet like in the blue box D&D or Metamarphosis Alpha rules. I could never get anyone interested. I lost it in the leaky pipe disaster that trashed a lot of my gaming materials.