Grand Theft Auto IV
I tried playing Vice City again recently, and it really served to reinforce my feelings about GTA4's progress. While it is basically the same game as before, it has succeeded in fixing and polishing a great deal of the franchise's issues. Going back, I found myself missing a lot - the improved map functionality, camera controls, dumbed-down police AI, not losing all my weapons after being blown up, etc.
At the same time though, it's easy to pick out things wrong in GTA4 as well: a lot of the freelance missions are gone (ambulances and fire trucks); you still lose stuff when you get busted; the limited number of weapons you can use from inside a car... in general, while I wouldn't say it's "as bad as" Madden, I feel a similar sort of effect, in that installment after installment is just slowly and incrementally working on the same formula, in a way that ensures leaving room for improvement in the next game.
Of course, unlike Madden, I find the GTA formula absolutely fun as hell. So I guess it's not too terrible that each game is just better than the one before it, and not necessarily as good as it could be.
Progress: Gave Up