That's a hard one. It's almost a 3 way tie between Capcom, Konami, and Square for 2nd place and Nintendo at 1st. This is based on how many games I own from each company. I think I own a total of 30 games over the decades (1985-2007) made by Nintendo. I have a variety of games from a variety of companies, but these 4 companies have remained a constant in what I buy each year it's going to be 1 of these 4 every time at least once.