I bought Dirt 2. The rest didn't really seem appealing. 9.99 for Dirt 2 is still a hell of a deal.
A warning to anyone on XP x64, this game will not work with the latest version of Games For Windows Live installed. You won't be able to create an autosave, meaning that you can't save your progress what-so-ever. You have to roll back to version 3.08xxx to be able to create an autosave. If you try to play online, you'll be forced to upgrade to the latest version of Games For Windows Live, and you won't be able to load your autosaves again until you revert back to version 3.08xxx. So basically, if you have XP x64, you won't be able to play online with your saved data, and if you want to play online and play single player, you'll have to switch between the current version of Games For Windows Live and version 3.08xxx every time you switch between the two.
After about two hours of play, I'm really liking it. I don't have a 360 controller, so I use my PS3 controller and it works great. I use a program called
MotionJoy that provides the proper drivers for the PS3 controller. It has a function that enables 360 controller emulation, making the PS3 controller appear as a 360 controller to Windows, so it works just like a 360 controller in any game that supports it.. you can even use it wirelessly if you have bluetooth.
I really like the tracks in Dirt 2. It has a great variety of short twisty tracks and long open ones.