I'm a huge fan of Tunnels & Trolls and by extension Monsters Monsters! There is just something about the basic T&T system that I find extremely satisfying.
The free preview of Monsterary of Zimrala is a nice, professionally done piece of T&T, MM piece of lore.
You can find the Kickstarter for the Monsterary of Zimrala here.
You can catch the daily Tavern Chat podcast