Interesting topic!
First, the games I played a lot of.
BRP games:
RQ 2 and 3 for many, many years (in Glorantha and Questworld).
CoC, several adventures, needed a new character each time.
Non-BRP games:
D&D 3.0 and 3.5
Champions
ShadowRun
The Fantasy Trip (Wizards, Melee and Into the Labyrinth)
Other games that I played for a while, but not really a full campaign.
BRP:
Stormbringer 1
Ringworld
Non-BRP:
AD&D 1st (What I started playing RPGs with)
Vampire: The Masquerade
Fading Suns
Paranoia
Middle-Earth Role-Playing (MERP)
Fantasy Hero
Cyberpunk
Psi World
Palladium
Teenage Mutant Ninja Turtles RPG (Uh, well, I was in high school and well...)
Robotech RPG (Damn, this is embarassing...)
I'd better stop.
Seriously though, I have some of the original TMNT comics and graphic novels and I have the entire Robotech series on DVD. They were pretty cool when I was 15 or 16.
I have a ton of other games, some of which I played once or twice and some I ended up not playing at all. Won't bother to list them all.