GTA 4 is the best game in the series. Looks better, plays better, solid story. One of the top next-gen games. Score: 9.7
You play as Niko Belic, a russian immigrant with a past that gets revealed the more you play the game. He meets up with his cousin Roman who with other characters will give him missions and help him throughout the game.
One of the new aspects of the game is your relationships with your friends, who not only give you missions, they also can have special perks if you hang out with them outside of missions. This includes discounted weapons, access to helicopters, and other things like that. Also the cell phone is a nice addition to the game because it makes getting missions easier.
The major difference in gameplay is the addition of the cover system and the ability to blind fire. The cover system while extremely helpful and life saving, sometimes can get stuck when your trying to get out because if your moving the analouge stick in the direction of some other nearby cover Niko will run and slide into that cover instead of exiting cover and running away. But thats not to big of a deal.
The game is set in Liberty City and is slightly smaller than San Andreas but has no wasted space which makes it a much better map than what GTA 3 was played on.
In my opinion GTA 4 has a very solid story, during which the game will occasionally force you to make a decision between killing 1 of 2 people or executing a person that you were sent to kill whivh is a nice addition to the game and keeps you more involved with the story and effects certain missions that you can recieve.
GTA IV is also the most graphically good-looking and realistic game that I have played. The world looks great and walking in and out of buildings has no load times. Pedestrians are very life-like, tehy're not just walking around, they are always doing something like smoking, carrying groceries, or running from cops. If you shoot someone in the leg they will fall to the ground and clutch their leg, if your driving 150 mph and smash headfirst into a wall Niko will fly through the windshield, if you hit someone with the car they will flip over the hood, smash the windshield, and fly over the top of the car, fallen enemies who haven't had there head blown off will be squrming on the ground pleading you to not kill them.
The Radio Stations/ Soundtrack is just as good as the other GTA's and the Talk Radio Stations and commercials are as funny as ever (I recommend "Integrity 2.0 with Lazlow). The Radio has a great mix of music so everyone will have something they like to listen to.
All in all GTA IV is a fantastic game, but its not perfect, no game is perfect. Its still one the best games ever and even though some people gave it a 1 out of 10 just because they don't like the series, the hypocrites still bought the gamefor some reason.
Graphics: 10
Gameplay: 10
Audio: 10
Value: 9.5
Story: 9
Overall: 9.7