If you prefer having your RPGs in PDF form, there's a Humble Bundle-esque site out there for you called the Bundle of Holding. There are only ever two levels of content in each bundle and the starting price is much higher, but there are typically three or four bundles active at once, each with a large smattering of books. Sometimes, they do other things, too, like print-and-assemble papercraft models or terrain. They even link the books to a DriveThruRPG account (if the content's available on the site) for backup and redownload purposes in case their own site goes down. Currently, there are two bundles compiling the entirety of the Champions 4th edition lineup (though one sourcebook has an incomplete PDF as of now; the scanners plan on updating the PDF and sending it to bundle buyers when they can get a complete copy), one bundle containing some books for the third edition of Heavy Gear (a game with a Battletech-esque setting), and one bundle containing the entirety of the Advanced Fighting Fantasy gameline (based on the Fighting Fantasy gamebooks). Previous bundles have included games and lines such as Traveller, both versions of the World of Darkness, Mutants & Masterminds, Shadowrun, Deadlands, Lamentations of the Flame Princess, Exalted, Paranoia, and many more. No D&D, though.