Haven't really played many racing games this gen, other than Driveclub. It's a pretty brilliant game, imo. But, haven't touched any of the others so I can't really fairly comment.

I've played all those except Project Cars and I'd vote Horizon 2 easily.

DriveClub... nothing comes closer. Best graphics and sound without question and a gameplay that stays perfectly in between arcade and simulation: the best of both worlds. Content wise the game is pretty rich too.

horizon 2 > driveclub.

Probably forza horizon 2.

Forza Horizon 2 for me, hands down. I've spent over 100 hours in it and I still have tons of stuff to do. I just bought Storm Island for $10 and I'm loving it!

Mario Kart 8 because it does count

Forza Horizon 2 for sure. I've been playing for a few days and would so far rate it 9/10.

haven't played a racing game yet.

uknow you're excluding a loooooooooooooot of people for omitting Mario Kart.