Originally Posted by
Max_Killjoy
The tangent at hand was settings, not systems.
On the subject of systems:
D&D
AD&D
AD&D 2e
WEG d6 Star Wars, every edition.
Multiple d20/OGL products, from the Thieves' World adaptation to a bunch of random stuff I picked up used cheap
HERO 4th and 5th (6th went full-lawyer-mode sideways, and anyway the guy who runs their forums started imposing a political-opinions litmus test on the moderators and decided I didn't pass, so I broke off any involvement with the place).
Every edition of Vampire through utter disappoint that was Requiem.
Multiple editions of Warewolf.
Read through and studied (but didn't directly play) all the other White Wolf products through about that time.
Traveller
GURPS (only read, not played)
Mechwarrior (Battletech-setting RPG)
Pendragon
Legend of the Five Rings (4th ed)
Mythras (read for reference)
The Burning Wheel (reading it right now as I get time)
The most recent Conan RPG (reference)
Literally scores of free and sample products off DriveThru RPG (mostly read through for reference)
And I'm sure that's not a complete list.
I even forced myself to read through some of Ron Edwards' pretentious little products.