GT5, Forza 3 or iRacing?

[Freshjive]

Rfactor with a g25 and your set

[Hallen]

It all depends on what you want.
Do you want bling with tons of cars and tracks that look awesome, but the driving experience is a bit like those old carnival car rides where your steering input was only marginally related to where you go (because you were actually on a mini train track)
Or
Do you want something that makes a real effort to provide you with as real of a driving experience as possible albeit with a more limited car set and a more limited number of tracks.

iRacing
LFS
rFactor

They all have pluses and minuses. I've driven them all. I would take any of those over any Forza or whatever console game.