I've got George Reeves, Dean Cain, Bill Murray and Tom Welling.There have been 7 actors that have played the live action Kal-El/Clark Kent...etc , on a TV series, name them and the tv series.
I think Dan Aykroyd was "Uberman" in the SNL 'What if Superman had landed in Nazi Germany' sketch, but I wouldn't count that one, either.