Here's a game I haven't played or even read or explored to any real degree: Dungeon World. Which is a shame because it has a fairly robust following with a DIY community of content creators.
I remember picking the book up while in a game store in New Orleans years ago and the reason I put it back down was IT WAS TOO THICK. That's right. I'm at that age where anything over 120 pages is going to make me think "Oh man... I can't commit to reading this." *sigh*
Of course a large bulk of the book is apparently rehashed lists of standard D&D tropes, such as classic monsters and spells. So you don't have to just read all that... it's reference if you need it.
The system seems to be simple. It's 2d6 and you just have to hit a standard target number. There's also a gray area so rolls are not binary. It is based on Apocalypse World, of course, which is where the system comes from. Here's a video about that's fun to watch, though I think he wasn't aware that this is Powered by the Apocalypse:
So yeah. This game is next on my to-buy-and-play list. Just as soon as my obsession with Troika! levels out.