Isn't the .38 Super still popular on the competition circuit, and in foreign countries that prohibit civilian ownership of "military" calibers?
If you really want to open the doors, we could throw in gems like the 9x23 Winchester, .41AE, and .400 Cor-Bon.
Yeah, a lot of Race guns are in .38 Super and it's big in Mexico b/c of the military cartridge ban. You just don't see many ordinary Joe's like me carrying them around. The 9x23 never really caught on and the 41AE was good but never made it either.
I have a Ruger Blackhawk Covertible in .38-40/10mm that is pretty fun to shoot. Love to shoot my S&W 610s as well.