The one with the most fans? Definitely Nintendo. They've been in gaming the longest of the 3 companies with arguably the most fans, so it goes with reason that the oldest gaming company has the most gaming fans.
For me personally, while I am a Nintendo fan, my first loyalty for gaming goes to Atlus. I'm getting way too many of their games...
-dunno001
-On a quest for the truly perfect game; I don't think it exists...