Soundwave on 21 September 2014
Valve I think, though they're already pretty huge, but I think Steam will just continue to grow.
To be honest though I think the game industry will start to become a lot like the movie business, where you have basically the same 5-6 big studios (20th Century Fox, Disney, Warner Bros., Paramount, and Universal) that control all the big movies and maybe some smaller indie studios that get in there once in a while.
