Huge GTA fan. Got GTA5 at midnight release. Beat it. The GAME PLAY is perfect, flawless, amazing. But it's the STORY that's the major shortcoming. I won't spoil anything but here are the problems I've had with it.
The story is predictable, down to the climax. The fact that Rockstar's trailers revealed a bit too much also dampens some moments.
Character behaviors are inconsistent, just as the Gamespot review said. Many major plot points are contrived, artificial and it's doubtful they would actually happen. Twists often happen abruptly and the gravity of those events isn't well conveyed.
The game has an identity crisis between serious drama and the absurd hilarity. It's not that mixing funny and serious is bad. Look at Portal 2, for example, or the previous GTA games like San Andreas. GTA V often times, after behaving like a carefree surreal fantasy action movie, expects me to become emotionally vested all of a sudden, when I just can't.
An example of this is Michael's family. They're through and through funny american stereotypes made to be laughed at, but at certain points of the game, the game intends to have you emotionally care about them as if they've all of a sudden became real people.
There are some real winners like the supporting characters, but some characters just don't work. Trevor is immensely entertaining, but his maudlin attempts at being emotional are just tough to take seriously. Franklin was never any more than a CJ clone. And the villain(s), I'll just say, they're forgettable.
The ending is a cliche and lazy copout that moreso made my eyes roll than get a serious reaction out of me.
The entire story gave me a headache. It was too persistent to be just a random comedy and it was too flippant to be taken seriously. For all it innovates, it's in too many ways a cliche.
I would still give the game a 9/10, and suggest that if you don't take the story too seriously, you'll love the open world and the great missions which are both second to none.