Here's something I'm obsessing over, of late: Swords and Wizardry, the open-gaming-license version of "original" Dungeons and Dragons!
It's a Gamist design, through and through; what's more, their design ethos is this - simple rules means something customizable and easy to pick up; it also makes referees more flexible and able to adjudicate on the spot, rather than being trapped by complex design.
I. Am. Fascinated.
Download the core rules (and a whole bunch of other cool stuff!) right here. It's all free!