Since TSR's Basic Dungeons & Dragons with the Erol Otus cover in the magenta colored box was my first rpg purchase way back in 1981, it seems fitting my last purchase was the wonderful retro clone Basic Fantasy Role Playing Game.
With all the free material of quality available online, including Basic Fantasy in PDF format, I've forced myself to be real frugal with actual cash expenditure on rpg books. But Basic Fantasy did it right for me. A free PDF led to a Lulu purchase of the perfect bound, publish on demand copy of the game. The cost of the book was, like ridiculously low, and with a shipping discount being offered it was a no brainer.
The game gave me the house ruled tweaks I wish I had thought of while retaining all the flavor of the great game I first came to love.
I have further modified my Basic Fantasy with the best aspects I find from LotFP (also available for free in PDF format), and all those folks making cool character sheets, free adventures, Game Master aids, etc. just make this product one of the best rpg deals going.