I never pass up a free RPG PDF to download. In another thread a new superhero game called Codename: Spandex was mentioned. Add one more to my collection
I'm sure everyone can find OSR games that are free. Hell, Basic Fantasy seems to always get a mention for example.
So I'm going to rule out OSR games. It's OK to mention them, but I already have a boatload of OSR games. I've got the fantasy genre covered several times over. Really, I'm good for elves, fighters, and armor class, THAC0 or otherwise. But, the masochist in me will probably download any new ones that use some sort of unique rules. Like Tricube Tales or Warrior, Rogue, & Mage.
My sample list of free games I like are;
1. Pocket Fantasy. Probably as rules lite as you should go, but is a fully fleshed out RPG.
2. Mini-6 Bare Bones Edition. A cut down version of West End Games Star Wars D6 rules, but now meant to be a generic set of rules for everything. I'm using it for Pirates of the Spanish Main.
3. Freeform Universal. It's barely a game, but I use it as a GM tool to resolve situations that my game doesn't cover. I.E. mass combat or a fight vs a clearly outmatched foe not worth wasting a lot of time on.
4. Stars Without Number. I'm just impressed because 90% of the full game is given away in the free version.
So what games do you like? Again, you can mention OSR games, but just know that I already have far too many free and paid fantasy RPGs to choose from already.
It's fantasy, but the overwhelming majority of Talislanta stuff is free (http://"http://talislanta.com/talislanta-library).
Cepheus Engine.
It can be called OSR Traveller, but all versions of Traveller are still in print (print on demand).
Over the Edge has a free version of the rules, the WaRP engine. It's mostly known for the setting, but the system is an interesting ultra-minimalist take.
Ars Magica 4th edition is also free, and the magic system is legendary.
Fudge is worth a look. It's a deconstruction of RPGs.
I haven't looked into it for ages, but Forgotten Futures was a fascinating work of love. It dates back to the 90s, and was an ever-expanding setting, set of rules, and original source material for Victorian/Edwardian scientific romances.
Heavy Ordnance got dated the moment Columbine happened, but it's another old fun game.
Mutant Future is a riff on Gamma World, based on Labyrinth Lord. Free no-art version.
Dungeonslayers. It's not OSR but attempts to emulate the style or feel of old school games but with a more modern streamlined ruleset.
There are two editions in English that I know of. 3E is about 20 pages but is fairly compete, I managed to run a brief campaign with it. 4E is much longer (150-200 pages) and includes a setting but is also fairly simple (though I gave not run or played it)
I've got some of my own on my website. I guess it's probably unfair to say they're my favorites but who said life is fair?
The Arcane Confabulation http://www.uncouthsavage.com/uploads/1/3/3/2/133279619/thearccon.pdf
Galaxies In Shadow http://www.uncouthsavage.com/uploads/1/3/3/2/133279619/_sf.pdf
Twenty First Century Plus http://www.uncouthsavage.com/uploads/1/3/3/2/133279619/fivestat.pdf
Old Bones http://www.uncouthsavage.com/uploads/1/3/3/2/133279619/oldbonesi.pdf http://www.uncouthsavage.com/uploads/1/3/3/2/133279619/oldbonesii.pdf
The barebones version of the Magnificent Barbarians of Lemuria.
Degenesis, hands down the most beautiful free RPG.
https://degenesis.com/downloads/books/
Opend6, the generified version of the d6 system from West End Games that was used for Star Wars among others.
https://ogc.rpglibrary.org/index.php?title=OpenD6
I've just thumbed through this, but it looks pretty cool. Legend of Zelda RPG.
https://reclaimthewild.net/