I bought SimBin's Race07 for the PC and all the expansion packs.
I finally experienced great force feed back, adjustable and awesomely intelligent AI, more car settings than I could ever imagined and sounds and damage to die for. It's so much fun to race against AI and have to struggle to come in just in the top 5 and the AI is set to just 85%. It's a pure racing simulator so there are no goofy levels or money/credit to attain......ya just race! I love it.
Now I just need to find a 20ft HDMI cable to get it showing on the 50in plasma and I'll be in heaven.
PS. In GT5, I did buy an oil change for my BMW GTR Race car and ran a couple laps on the 'ring but quickly went back to Race07 because the force feed back in GT5 is so awful.