As you can imagine, NFSW is an online version of Need for Speed, set in an expanded Palmont City. Do I need to say more?
This game is FREE and I recommend that you download it immediately if you're into racing games.
http://world.needforspeed.com/
There's a really nice range of cars on offer, and you can play either single player or multiplayer. I haven't played a whole lot, so I can't offer you much more wisdom.
Once you do get it, add me (Dunnybrusher).
The download isn't too big either. Less than a gigabyte.