This was my favorite thread on the old r/OSR. So is your favorite system/systems?
I’ll start:
Basic Fantasy - BF gets overlooked a lot because the print books are sold at cost so I think it ends up being a lot of peoples introduction to OSR, but I keep coming back to it. The modules are really well written.
Old School Essentials - Just got the Rules Tome and I love it, though I haven’t had the change to dig into a game with it yet.
I think, as unfair as it is, my favorite system is probably the one I’ve been focused on making. I’d call it NSR since it isn’t really a clone of any of the actual old school systems. It doesn’t have a name yet, and the only copy lives on my Nextcloud server for now.
My favorite actually published system is Whitehack. It’s so elegant and flexible that my system takes a ton of inspiration from it, and really just slightly tweaks it to make startupbquicker for players, and provide some more targeted tools for GMs.
And my favorite actual old school system is 0e. As weird and clunky as it is in some places, it really does feel like they got it right through first time. My system could be pitched as a 0e hack (is it still a hack if it brings almost none of the original mechanics unchanged?)
Good luck with your new rules set! Let us know when you have something you can share!