I don't think anyone mentioned the GTR series yet. Back when I used to like racing games I regarded them quite highly. They're also victims of StarForce DRM making them unplayable on modern Windows today.
Fun fact, people/founders of SimBin that made GTR games went on to found Slightly Mad Studios that made NFS Shift games which is why they're so damn good.
GTR series is really fun, complicated and I've known Project Cars series is pretty much spiritual successor to that.