Stardock are good for sure, but i'd still go with Valve. I mean, who else makes 7 day updates with hilarious amounts of detail in them like Valve have done this week? Pretend leaked videos? clues in their cinematics about upcoming games and patches? a whole viral backstory between the spy and the sniper that sticks to the lore of the game when releasing their updates?
Plus, the number of jobs they create. I shudder to think of the number of Indie projects that have gone under due to lack of funds. Valve finds developers and hires them to finish their own games, gives them office space and awesome equipment and unlimited resources to work with, then gives them a hugely successful platform to release on. Portal for example.
Plus all the indie games they support by selling on their Steam platform. World of Goo, And Yet It Moves, Peggle... all these games would have had a fraction of the sales without people like Valve.
i find it so hard to not be a Valve fan boy, but i literally struggle to find things they do wrong. Perhaps they should be releasing their episodic content more frequently, but you know it's going to be worth the wait
Oh, and maybe they buggered up the achievment unlocks in TF2 now. I'm kinda miffed about that!