I am either very interested in trying, or have tried and enjoyed basically all of the systems I see mentioned so far.

A personal favorite base system of mine that counts as pretty rules light that I might also suggest here, would be the Tiny D6 line of games from publisher Gallant Knight Games.

They have a simple base d6 system that is really easy to learn, and then lots of setting/genre books that take the base system and add just a bit to it to make it fit thematically. The whole line is also super modular, so you can take additions from one book and pile them onto another one to dial in closer to the theme you’re aiming to hit for a campaign. All of the base books are full systems, so you can buy any one of the main books and be ready to play. The one book covers the DM/GM and however many players.

• Tiny Dungeon is the base fantasy system and covers typical high or low magic fantasy with swords and shields and the like.
• Tiny Cthulhu adds the horror element and a corruption mechanic, as well as suggestions for Pulp and Noir.
• Tiny Frontiers: Revised makes everything Sci-Fi and adds in giant vehicle (space ship) mechanics.
• Tiny Mechas and Monsters: Evolved takes the Sci-Fi and throws in giant mechs fighting giant Kaiju monsters, where the players can play as either side.
• Tiny Supers takes the base system and throws in super powers as options in building characters, and provides guidance on how many powers to grant characters to fit the “level” of the supers. Be it neighborhood, city, national, galactic, etc.
• Tiny Taverns is a big social bit, of the characters staying in one place running a tavern or other shop, and largely interacting with just one town
• Tiny Gods starts with the group (GM and players) working together to create the world and the races in it, then has suggestions for playing in that world as a demi-god, or you can jump to any of the other books to play in the new setting you’ve created.

Then they have many more that I haven’t even broken out here: Wastelands, Gunslinger, Pirates, Zombies, and even more I can’t think of off the top of my head at the moment. But you learn the main dice mechanic, and you know 80-90% of what you need to play any of them.

But it definitely sounds like you already have a good place to start selected, and lots of really great options to investigate from there! I hope you all have loads of fun, and don’t feel compelled to stay tied to any one system, feel free to change it up from campaign to campaign, or to throw in one-shots as breaks in longer running campaigns. Sometimes those one shots can help keep players excited, or help provide a bit of a mental reset between story arcs!