Well I'm a bit late to be saying this...considering I bought GTA4 day one. But I think it was a epic fail and definitely doesn't deserve a 10.
Although I loved the game while I was doing the actual storyline, after I beat it...the game got incredibly boring. I thought the assassin missions, get cars for Brucie, and the LJ missions would be fun...turns out they weren't.
Seriously why not put demolition derby or insurance fraud (like Saints Row) instead of a broken bowling game and a pointless pool game.
R* took out the fun and replaced it with realism.
So 1 month after beating the game, the only exciting thing so far was finding the hidden heart in the Statue of Liberty (happiness).
I give the game 7/10 and I'm sure Saint's Row 2 will be WAY better than it.