I have a work-in-progress list here, strictly games I would consider “must play” in the genre. Notably missing the Ridge Racer and Tokyo Xtreme Racer games because I haven’t played enough of them to have an opinion.
Mostly arcade and simcade racers though. If you’re interested in sims:
For modding, Assetto Corsa is basically the modern rFactor.
For offline racing, Automobilista and Raceroom have pretty solid AI. Note: Raceroom’s pricing model is dumb, kind of like iRacing just without the subscription.
For career mode, Project CARS 2 (not 3) is basically the only sim that even tries.
For online racing, ACC and iRacing are unmatched.
For rally, you’re already playing DR2. Richard Burns Rally is also shockingly good for its age.