GOG.com - DRM-free game store, selling both new and old titles. No clients required.
Green Man Gaming - A digital distributor for video games.
Origin - Origin is your new digital playground. It’s where you go to find the best that EA has to offer.
Desura - Desura is a digital distribution service for gamers, putting the best games, mods and downloadable...
Humble Bundle - Buy a bundle of games, you decide the price, and support charity in the process.
Gameflip - Buy and sell video games from people not companies