I don't do game reviews oftn... but since the interwebs is a-buzz with it... and everyone's been giving the game 10/10 scores, I figured I'd give you my own review of GTA IV now that I've beaten it.
I'd like to start off by saying that the game deserves all the great reviews it gets. It's absolutely brilliant. They took everything that worked out of the last generation of GTA games and pretty much perfected them, and took out everything that sucked (all the fantasy bits, like the jetpack and such). Everything feels tighter, more cohesive, and once you get used to the somewhat non-standard control scheme, everything flows fantastically.
The protagonist this time around is someone you actually care about... someone who's not out to build an empire from the ground up, but to make a new life and to exact revenge on a certain somebody. Being that I'm always seduced by the revenge ethos (mmmm Count of Monte Cristo) I love it. And the game really feels like you're tooling about in Manhattan... or Brooklyn, or Jersey City (eww).
There's a lot more I could say about how good the game is... but you could read about it, or better yet, go out and get the game. I do, however, have a few complaints... the graphics, being such a huge world, occasionally let me down, usually when characters are talking (the talking animation isn't exactly the best... though character models are otherwise brilliant, and the variety in citizens in Liberty City is unprecedented), or when there's way too much to load. The cover system is a little unwieldy at times, sometimes latching onto the wrong object, or latching onto something when I'm meant to be getting off another object. Even by the end of the game I was having a little difficulty with it. The radio stations are great... but given the length of the game, they got rather repetitive.
But every game has its faults. It's pretty fucking brilliant. If you've got a console and you've got $60 to spend, this is the game you should be making a beeline for at the store. Buying anything else would just be silly.