I have to put in some love to GRID too.
I bought it for a loust $3.74 on a Steam sale, and damn, it's beautiful, it plays wonderfully, the level of challenge is just right for me, but there's a wealth of options, including driving assists to turn off, and...
(I'm sure other games have done it but..)
The limited rewind feature! It just utterly destroys the one thing I always felt held back racing games as a genre. We've all done it, from Mario Kart to Gran Turismo, had a perfect 4 laps or so, we're coming up to the final corner and we spin out, and 7 computer players zip by. Cue intense frustration at a minor mistake costing you a solid well run race.
With rewind, you just slap the button, go back 5 seconds, and try again, however, it's limited, so it's not a cheat, and it penalises you financially for using it, so it's a tradeoff.
On top of that, every damn thing about GRID is just so polished, it's just been really pleasing every moment since it finished downloading, and the use of a 360 pad makes it so much better!