What Game Systems Do You Have?

[Ogre Mage]

D&D 2E, 3.5E and 5E, TORG Eternity, Savage Worlds Adventure Edition, Vampire the Requiem, Shadowrun 4E, Earthdawn, Numenera, Basic Role Playing, Mutants & Masterminds, Talisman Adventures.

 

[pogre]

I have way too many. I need to sell some. I used to be really good about selling anything I had not played in a couple of years. I'm way overdue for a purge.
D&D 5e
Savage Worlds
Call of Cthulhu
Traveller
Runequest
WFRP 1e
WFRP 2e
WFRP 4e

That's what I'm keeping - the rest is going up for sale this winter.

 

[ShinHakkaider]

Just going from memory:
PF1
PF 2
D&D 3/3.5
Champions 4th Edition
HERO SYSTEM 5th Edition
Star Wars (d20)
Star Wars (FFG)
Dragon AGE
Modern AGE
Fantasy AGE
D&D 5e (Never and mostly likely WILL never see use)
Alien
Mutants and Masterminds 3e
DC Heroes (MEGS) 2nd Edition box (Sealed)
DC Heroes (MEGS) 3rd Edition
Starfinder
CyberPunk
Star Trek
FantasyCraft
SpyCraft
Cypher System
Mekton Zeta
FATE
Marvel Mulitverse Role Playing Game

A few years ago I purged most of my Dungeons and Dragons books from BEMCI up to 4th Edition.
I kept some adventures and books from Advanced and Basic (Like Keep on the Borderlands, Village of Hommlet, TOEE, SCOURGE OF THE SLAVE LORDS, QUEEN OF SPIDERS and the single versions of the modules. Bill Willingham signed my copy of G1-3 so I was definitely keeping THAT.) I got rid of a literal bookcase of 3rd and 3.5 books and adventures and all of my physical Champions books for 4th Edition except for the Core Rulebook which I wanted to get signed by George Perez but never did...