Just finished the game and I have one word to say... WOW !!!
As a person how hated ALL the previous instalments in the series, I must say that I am highly impressed.
Everyone who found the previous instalments frustrating and annoying will find the difficult of this installment much more balanced, yet challenging.
The amount and variety of missions and other activities are great, and the amount of dialogues and TV shows are amazing !
The graphics are very good (not excellent due to the lack of AA and the low FPS), and I liked the weather effects !
The sound is superb because of the excellent voice acting and soundtrack (including the songs in radio stations).
The multiplayer is very fun and highly addictive !
It is probably one of the most genius feature Rockstar has implemented.
The video editor and the ability to records the gameplay are very nice features which add a huge motive to ride the city after finishing the game and of course... increase the replay value !
And now for the part that made so much fans disappointing...
Yes, I'm talking about the unreasonable and extremely high system requirements.
I have 4GB RAM, Intel Core 2 Quad and Nvidia Geforce 9600 GT (512 MB VRAM) and I suffered from low FPS at some points through the gameplay (especially when driving in a heavy traffic roads), but I know that Rockstar will iron those issues so it's temporary and those issues are tolerable anyway...
GTA IV is simply one of the best (if not the best) game I have ever played.
Like I said above, I am not exactly a GTA fan, but I found this game very enjoyable and I recommend you all to check it out!