Do you want us to vote for our personal favourite? If you are asking us to say objectively which game company has the most fans then it is the silliest question since there is a company that has the 15 highest selling games of all times and whose games are usually top 5 worldwide on a weekly basis.
Objectively and subjectively the answer for me is Nintendo by light years.
Biggest Pikmin Fan on VGChartz I was chosen by default due to voting irregularities
Super Smash Brawl Code 1762-4158-5677 Send me a message if you want to receive a beat down