the Black Hack

It was a fast read, and I like a lot of the streamlining. You can tell the author loves D&D but doesn't like getting bogged down with minutia and fiddly rules. It's still basically a D&D game, but it's a lean, fast beast. Even leveling up is simple and quick. When I finished reading the spell lists it made me want to run Dwimmermount again.

For less than $5 you can get the Black Hack and two supplements with a "procedurally generated" village and extra classes.