Which game is better and why: Forza 3 Motorsport or Need For Speed Shift?

I own an xbox 360Which game is better and why: Forza 3 Motorsport or Need For Speed Shift?
Based on trades, I would say Forza 3. There were used NFS Shifts the day after the release at the gamestop I work at.Which game is better and why: Forza 3 Motorsport or Need For Speed Shift?
forza 3 has better racing gameplay and its a little easier to play but nfs shift has better graphicsWhich game is better and why: Forza 3 Motorsport or Need For Speed Shift?
forza motorsport 3 every gaming site gave it a better review then nfs shift. plus it has 100 tracks and 400 cars!!!