[Zeroblade]

As of right now, for PC I hear Assetto Corsa is good - more on simulation than arcade like. Otherwise I second Project Cars (even though game isn't out yet, its looking to be the base racer ever made).

Available now for cheap though, I strongly recommend Need for Speed Shift or Shift 2. The biggest seller NFS Shift provides over Gran Tursimo and Forza is the sensation of speed... and the fear that goes with it. The game is about 60% arcade, 40% simulation. This is the only game I know that made me scared going flat out even if I was using a controller.