Have you ever considered Midnight Club, or are you into racing simulators?
I've got Midnight Club LA. That was a pretty fun game but I got bored with it kind of quick. There were plenty of tracks but after a while they all started to seem the same. I'm mostly into sim's but I love a good arcade racer too, like Motorstorm Pacific Rift, and Grid was a lot of fun too. Grid 2 is coming out in a week and a half, but right now I'm saving all my fun money to build a gaming PC so I won't be buying any more games until later in the year.