If you don't have this game you are not a real gamer,just you are into the past.GT4 is King of all racing games.
I am playing a lot of racing games like NFS series (all finished except Undercover),Race Driver GRID,Flatout,Test Drive Unlimited and more that i am not remember.All games are kind of boring,they are not into the real life like GT4,the driving is not like GT4...THOSE GAMES ARE NOT SAME LIKE Grand Turismo 4 .
I started to play Grand Turismo when i was 9 years old(before 5 years ago),The PSone and the pure GT1 was kind of "hardcore" game for me,( i mean very hard but i was still playing it).Right now i am playing Grand Turismo 4 with very big pleasure.
GT4 has amazing graphics for a PS2 game,when you go the car for wash you can see that the car is very detailed.
I learned much more about the cars(categorys,HorsePower and more),The game is very big,but when i mean very big i mean BIG !
The events,the licenses ,the menu,the fast cars,the endurence,all those things make the game perfect.