TOCA Race Driver 2 remains one of my absolute favorite racing games to this day. It's perhaps the most complete racing game, because it not only offers great tracks and an incredible variety of racing series and handling - no, unlike the perhaps even more realistic, but far more soulless games like Grid, Assetto Corsa and Gran Turismo etc., it is framed by a story. Even if it is admittedly a bit clichéd, it keeps you hooked.
I don't know how many times I've played this game over the past decades, but it never gets boring. Besides NFS Most Wanted (2005), perhaps the best racing game ever!