I agree with Steve on iRacing, if you have to pick one... cover most of the major tracks in the U.S. in different configs... you will not find a nissan 370z on there but you can get pretty close in terms of weight distribution and power
I too am one of the suckers in the 100% club!
definitely not getting my money's worth but I like to have the option... wiser money will buy only the tracks and cars they need and upgrade as they go along
Steve mentions the "tire model" in iRacing... they just upgraded the math and physics behind this and they call it tire model 2.0... it is a big step up in terms of real life feel and response
Steve, you should try forza 4... it will prob exceed your expectations in terms of realism