Here's my list of my personal favourite systems:
(For context, these are all some variety of rules-lite,)
- Thirsty Sword Lesbians (https://evilhat.com/product/thirsty-sword-lesbians/) - PbtA, emotion driven narrative drama. Each playbook has an internal conflict that can be very fun to figure out.
- Orbital Blues (https://soulmuppet-store.co.uk/products/orbitalblues) - sad space cowboys just trying to survive in a space western world. Also has some great mechanics to set up a character's backstory and connection to the world.
- Mothership (https://www.tuesdayknightgames.com/collections/mothership-core-rules/products/mothership-players-survival-guide?variant=41210327269465) - sci-fi horror. Very easy to learn, plus the player book is free!
- FIST (https://claymorerpgs.itch.io/fist) - PbtA-ish, paranormal mercenaries doing good where they can
- Orbital (https://mouseholepress.itch.io/orbital) - NDNM, GM-less, characters working together against the backdrop of an interstellar war. Like other NDNM games, has fun character options and playbooks.
- EXTREME MEATPUNKS FOREVER (https://sinisterbeard.itch.io/meatpunks) - PbtA, fight antifacists in a meatmech and maybe kiss your friends. Weird in the best way and one of the funniest rulebooks I've read.
- Mobile Frame Zero: Firebrands (https://lumpley.itch.io/firebrands) - GM-less, romantic ace mobile frame pilots. Has some very fun question based mechanics.
- Monsterhearts (https://buriedwithoutceremony.itch.io/monsterhearts-2) - PbtA, messy teenager drama, as a monster.
- The Almanac of Sanguine Paths (https://montfordtales.itch.io/the-almanac-of-sanguine-paths) - solo tarot based werewolf journaling game.
And I'm going to give an honourable mention to The Beginning is the End (https://adam-west.itch.io/the-beginning-is-the-end), because it's a game about making characters.