Basically it is a 2' x 3' poster of just about every RPG out there right now. I'm sure it is missing some and the organization needs a little work, at least for my preferred games, but my games are in there. Unless you've played them all you are bound to miss some/misplace some. Of course this is only as current as 2012.
The poster is $14, which is a good deal if you've ever priced out getting 6 square feet of full-color map printed. It also comes with a pack of stickers marking what games you've played (or maybe would like to play?). You could also use this map to try and pick a new game to try. For some gaming groups the $14 would be well spent if it cuts down the decision time on selecting a new system to try.
I didn't think I've played many different games, but when I plotted it out I was a bit surprised. This won't blow up enough to see the games, so you should just head on over to Inkwell Ideas to see the map for yourself.