Star Wars. By a long shot. Look at how many games have came out since the 70's...

Pokemon...seriously.

There seem like there's a Pokemon game for at least 2 systems every year.

Naruto is getting up there now with the 8 different fight games and the two same but diff storyline games for the ps3 and 360.

Probably Mario. But even with Mario being used so much, no one complains. Maybe we should talk about the franchises that are milked and people complain about. I don't mind playing 2 to 3 Mario games a year haha.

Other than that definitely Madden, Guitar Hero, and apparently Singstar. The sports and Music genres in general I suppose.

But in pure amount of titles, it goes to Mario.

halo
guitar hero
tomb raider.
PES.at least in fifa EA improve the graphics.
they are not milking mario. i dont like mario or nintendo but they change something with every new game.

Now that others have mentioned Madden, I'd have to agree with it as being the numero uno milked franchise.

Branch Franchises are their own franchise.. Like Pokemon Ranger is a franchise, Pokemon Mystery Dungeon is another and Pokemon: _____ version is its own franchise.

The only franchise sony has ever milked has been Gran turismo..

Mario and Guitar Hero

Sims, no matter how you twist and turn it :p

Halo is getting there nowadays...

Final Fantasy

Singstar

Definitely singstar....but Rachet and clank is definitely getting there with 9 games in 7 years.