Impossible to answer for me. Would probably be Touring Cars.
The best racing happens with cars that requires proper driving skill, and not only great reactions and timing, when taming the car combines with racecraft then it is great. So that is either some down to earth cars that aren't ultra stable and has perceivable edge, or if the cars are very stable, such as with crazy downforce, then it has to be horribly overpowered, to highlight the edge.
Modern race cars are so fast, and at the same time looks so slow. Make them to use tire sets that would last at least 500 km racing, and limit wings for less drag and less fuel consumption, and you'll see more driving then.
Make me FIA president lol
I dislike modern racing that is all about reaction, no rhythm, no dancing, and it shows when you spectate such racing.