TORCS - TORCS, The Open Racing Car Simulator is a highly portable multi platform car racing simulation.
Forza Horizon - Forza Horizon is a Marvelous, Action-Adventure, Racing, Single and Multiplayer video game developed by Playground Games and published by Microsoft Studios.
TrackMania - The most popular online PC racing game.
RaceRoom - Race with real drivers, cars, tracks and series in a realistic sim
Need for Speed - Official site of Need for Speed Payback, an action driving fantasy that's the newest game in the popular car racing video game franchise, Need for Speed.
Speed Dreams - Speed Dreams is a 3d cross-platform, open source motorsport simulation and racing game.