If we’re talking individual games, there are a ton to choose from and it’s nearly impossible to measure them all. If we’re talking franchises, the discussion become a lot easier. I don’t have time to do all the research right now, but here are a few names that definitely deserve consideration:
Pac-Man. One of the truly amazing success stories of consumer marketing period, much less video games. This little yellow dude’s been everywhere: adventure games, puzzle games, racing games, and, oh yeah, the occasional maze where he runs around and eats lots of stuff. All kinds of completely unrelated Namco games, from Tekken to Ninja Assault, put him in somewhere. And it’s still going (IIRC, Pac Man World 4 is already in development). Let’s not forget all the books, toys, cereal, TV shows, songs, t-shirts, you name it.
Street Fighter. In terms of popularity, fame, name recognition, and almost unbelievable impact on the entire worldwide videogaming industry, no other fighting game is even close. Of course, you have to include the two spinoff lines, EX and Alpha, both tremendous successes in their own right. Such a huge phenomenon, even Capcom’s other fighting game franchises were quickly shoved out of existence. There are intense Street Fighter 3: Third Strike competitions to this day. Think any other 1999 game is even close?
Super Mario. Even if we exclude the old Donkey Kong and the unrelated spinoffs (Mario Tennis, Mario Golf, etc.), it’s been a pretty phenomenal run for the Italian do-gooder. That he’s been on every Nintendo console ever made is impressive; even Sonic The Hedgehog can’t claim that.
And a relative latecomer, but definitely catching up fast, Dance Dance Revolution. THREE different versions for three different countries, multiple platforms, and still incredibly popular in more places than you’d think possible. Furthermore, with the latest trend toward “active” and “fitness” related video games, it’s only going to get even bigger with time. There have been similar games, but none of them have had the top-down appeal or international corporation-financed marketing juggernaut the original has.