A good racing game?

what type of racing? arcade? sim? rally? circuit?

Gran Turismo :)

Big Rigs: Over the Road Racing

If you like simulators, check race 07 with all DLCs, perfect game if you have good wheel.
Also you can wait a bit for upcoming Assetto corsa game which will be masterpiece, check out steam greenlight

Race 07 is really good, if you are looking for a simulation-style racing game. Pricing for this one can be a bit odd, as you can get the game with its expansion STCC for as little as the core game itself (and sometimes even less!) in some places. Note that if you buy it with the STCC expansion, it will probably be sold as STCC the game. On steam they are sold separately (3€ each). And don't let the low price fool you, Race 07 offers a good amount of game for your money.

Project CARS

there is a free one; raceroom.

Look up Richard Burns Rally. Forget finishing the race, if you are a bad driver, you won't even finish the first corner.

I've been playing NFS Shift 2 Unleashed, and it's not so bad, though it's a bit hard I guess? It's not the best racing game but I have been having fun and it looks pretty good dispite it's age. I've been using a rumblepad 2 cordless too .. people say that using a wheel for it makes it a lot better.

GRID

Need For Speed Underground 2 duh