Stardock comes to mind as the Obscure Store That We Probably Haven't Heard Of. But unlike Stardock, Steam was also a DRM platform, the first to implement Carmack's observation ("The Internet is the ultimate dongle.")

In retrospect, it seems to have worked out pretty well for the company and its customers. Gabe Newell has proven to be a more benevolent dictator than his counterparts at Apple and Microsoft.