Well, I have to say, I honestly was not looking forward to GTA IV whatsoever 2 months ago. But then a little things called the gaming media began to play the actual game, and well hearing that a GTA game actually plays well was sufficient to entice me over. Boy was I glad I drank that kool-aid too, it's damn tasty.
The game itself is massive. Not the game world itself, mind you, it isnt very big, you can probably get across it in 10 minutes taking your time, less once you learn the city. However this is a full fledged city, with lots of detail. It believable enough. There are lots of things you can nit pick at (the recent Penny Arcade about GTA IV is an example of it), but there isnt exactly any reason they really detract from the experience.
The combat is fun now, the story is brilliant (although it seems to borrow a little too much from crime movies for certain missions and themes), and the amount of fun you can have simply randomly driving around is impressive.
The amount of content in the game is mind boggling, hours of TV, several sets of real Comedians, and god knows how much radio content there is. Most of it is genuinely hilarious, if you have a sense of dark humor.
There is considerable questionable material content in the game as well. Well pretty much all of it is adult oriented, but then again the game is not aimed at the tweens of today. Also the primary character of Niko doesnt exactly jump for joy at the prospect of genocide. So for me the fact that you can be incredibly evil in the game wasnt an issue. The worst I've done is run over swarms of pedestrians, which by GTA standards is quite tame.
So when it comes down to it does GTA illicit a purchase of your hard earned dollars?
If you've enjoyed past GTAs then obviously it does. If you've been interested in GTA in the past but always been put off by specific titles then you also should. If however GTA has never sparked an interest to play it then this certainly will not convert you. If you dont like open world games you arent going to start with this one either.
So, if you think you'd like it, what are you waiting for? Go get it!