I think only Nintendo has the innovative spirit anymore and that is shown through their game and system design and flagship games. Even if it comes off being gimmicky at times.
Telltale was only really innovative their first year, when they created the quick release episodic format, that other companies are now copying. Valve attempted the episodic distribution as well but really failed. Valve got the whole digital download service going through Steam though.
Now Telltales' 'claim' to 'innovation' has something to do with a Pilot program to give aspiring designers a chance to create new games series.