I think GTA IV had a great story. The problem? You control the character after the cutscenes.
I mean, Niko is treated is treated as someone who wants to turn over a new leaf and seems level-headed.
The cutscene ends, you get in a car, and starts running over everybody on the road. 
No consistency. That is the problem of storytelling in open-world games.
They could make sure you cant kill innocents, but fans would hate that.
Thats why I think, for the next GTA, Rockstar should this: main game with wacky character and story. Then, release DLC with more serious tone, where you cant kill civilians.
That way they would be able to keep their fans happy and still have the quality of story.









