VDrift
Even tough VDrift is still in it's early stages of development, it's already playable. Features
- Simulation-grade driving physics
- Tracks based on famous real-world tracks
- Cars based on real-world vehicles
- Competition against AI players
- Mouse/joystick/gamepad/wheel/keyboard support
- More...
TORCS
Also, there are various sites on the Internet dedicated to TORCS with additional content (such as cars, tracks, documentation, patches, etc.), which I am sure you will find interesting once you start playing.
TORCS allows you to drive in races against opponents simulated by the computer and to develop your own computer-controlled driver and features more than 50 different cars, more than 20 tracks, and 50 opponents to race against. Your can steer with a joystick or steering wheel, if the device is supported by your platform. It is also possible to drive with the mouse or the keyboard. Graphic features lighting, smoke, skidmarks and glowing brake disks. The simulation features a simple damage model, collisions, tire and wheel properties (springs, dampers, stiffness, ...), aerodynamics (ground effect, spoilers, ...) and much more. The gameplay allows different types of races from the simple practice session up to the championship. Enjoy racing against your friends in the split screen mode with up to four human players.
Download TORCS
Super TuxKart
This describes the game best:
See the great lighthouse or drive through the sand and visit the pyramids. Race under water or in space, watching the stars passing by. Have some rest under the palms on the beach (watching the other karts overtaking you :) ). But don't fall into the volcano.
You can do a single race against other karts, compete in one of several Grand Prix, or try to beat the high score in time trials on your own.
Download Super TuxKart