Dirt 2 or NFS Shift?

[Barozi]

DiRT 2 for sure.

I mean Shift is a good game, but still far away from being realistic. If you liked GRID (which you did) then you'll love DiRT 2.
The game features the best racing graphics (at least until Forza 3), Also the singleplayer mode is much longer than in Shift (according to IGN).