IV Lives up to the hype, it's the best game in the series, but it does still have it's flaws..
Lets start with the good, shall we?
Immersion: GTA has always been about immersion. Sure, there are oddjobs and missions, but it's structure is free form. From the second Nico steps off the boat, you know there's a grand structure here. It's like a modern day Oblivion in terms of scope and immersion.
Graphics: The graphics are excellent, the framerate problems aren't as bad as some people make them out to be, but they do have the occasional stutter, but everything is acceptable, with the exception of a few seratted edges, and a short draw distance, but with so much on screen at the same time, you can forgive these flaws, as everything else is slick and gorgeous. The animation is also very well complimented and realistic.
Gameplay: Okay, GTA's core gameplay may seem the same off the top, but there are many changes. Each weapon truly feels unique and realistic, and using them is just as fun, I admit, even though I would never live my violent fantasies in real life (Which is another plus to the GTA games, violent escapism with no real people hurt. I still wouldn't give this game to anyone under the age of 17 though...) this game fully realizes them, I was worried that the blood count and carnage wouldn't be as fulfilling, especially considering that many games these days pass off blood effects as the cliched puff with no decals. I miss decals, but while you won't have pinky-violence style heads popping off like in the previous games, the blood is exquisite and it drenches. In a similar fashion to Goldeneye or the original Perfect Dark, subtle patches of blood soak through clothes where bullets hit, rather than over the top bullet holes. Blood spatters the screen in up close and personal hits, including hits on Nico, and the blood spurts realistically and the decal textures are great, also gone is the ridiculous 'pool' of blood from past GTA games, with the exception of headshots, in which the damage on the head leaks out a small, realistic patch of blood that drips down ledges and other surfaces. Hell, blood even appears on cars, whether it be from running people down or shooting them while in the car (Or having yourself shot in the car). Now let's talk other things, the cars handle excellently, a little exagurrated, but it adds to the fun and destructive nature ofthe game. It's always funny when you see a cop car fall off a freeway overpass just to explode, and even if it hurts your character, you can't deny the adrenaline that pumps through you when you fail to slam your brakes in time and you fly through the windshield (Remember kids, click it or ticket!). Much of the gameplay would be hard to summarize without going into huge detail, so that is all I'm going to cover. The rest, which is all great, I shall let the player play for themselves to find out about.
Now, let's talk about the bad...
MULTIPLAYER. Multiplayer is fun... when it works. The game is riddled with strange bugs, where your console will crash trying to load the multiplayer game. That black screen is starting to look worse than a blue screen. I am hoping, rockstar will fix this in the future.
The story: The story is a mix of good and bad. I was severely disappointed to find out that, after hearing the game had a brilliant story, that it had many cliches of past GTA games, as well as the bad Reservoir Dogs style dialogue (F-this, D**khead that). Some dialogue is funny, some is just annoying. At least the actors are up to snuff. In the long run, the story is interesting, and Nico is a good character, but the missions are often cliched... kill drug runners, be a mafia hitman and find the rat, it's still fun to play, but it doesn't really make for great story.
Overall, GTA IV is a massive improvement over all previous titles, and is the greatest game existing on the 360 to date right next to BioShock, but does it deserve a 10? No. It has it's flaws, and they need to be addressed appropriately. But are these flaws serious enough to say 'This game is bad?' No. This game is a masterpiece. Even with it's flaws, it's greatness overcomes them in spades.