If it’s a PbtA please expand on your system of choice!
I’ll start:
I really enjoyed Sexy Battle Wizards, but I think The Witch is Dead speaks to me more. I like player characters just being little weak dudes and struggling against normal stuff. (both of these are free by grant howitt and 1 page of rules)
I also enjoyed rude detectives, it has a surprisingly juicy dice system for a game that’s just 4-5 pages. It’s themed around child detective stories.
PbtA I like magpies stuff, like avatar and root, but my favorite until now was Fellowship 2e I think. Just so extremely versatile, and it’s a joy to give a lot of narrative control to players.
Last one is kinda cheating: my current favorite game is rules light within it’s genre. 13th Age is the easiest ‘dnd’ I’ve ever seen, and the amount of dumb rules and bookkeeping it prunes has reinvigorated 20f games for me! But compared to other games, it’s still a bunch of rules of course.
I really like Fate but I’ve struggled to find a good group for it. I tried to run it for my DND group and it didn’t really go well. I think partly because they didn’t know the system well and approached it more like DND - very zoomed in on their character rather than the more “writer’s room” style that fate can do well.
I had a lucky group to play it, where we often try to shoehorn writers room style play into 5e to it’s detriment.