I’ve had the fortune to drive a bunch of different tracks, but probably my favorite has to be Grange Motor Circuit in Apple Valley. It’s a very rough, physical track with a lot of very strange corners that were always challenging. One of the hilights of the track is the 180-degree, off-camber, uphill-on-exit corner near the back of the track.
Others:
Adams Kart Track
Moran Raceway
SBR Motorsports Park