GT5 is the best simulator at the moment (Forza is terrible btw).
If your looking for action packed racing, this is not for you. I would recommend something like burnout, midnight club etc (not need for speed though. nfs is the equivelent of cod for first person shooters).
Being a trophy hunter myself, this element of the game just takes the piss to be honest. It's ridiculously difficult and getting a platinum would take a lifetime unless your on crack. For example some trophies are only gainable after completing 24 hour races. Are you serious?!. I mean, what are they trying to prove by putting shit like this into the game?. I should get paid like lewis hamilton or even more for completing a 24 hour digital race. Obviously everyone complained and they fixed this shit up to enable you to save midway through a race so the next time you turn on your ps3 you can continue, but this still takes the piss and I will not attempt anything stupid like these races.
Overall a very good high quality game. A must buy for car enthusiasts. A very challenging game. At least if your successful at this game, then you get recognized and get given opportunities to become a real life racer in the real world to earn real money and get real poontang.