Those classic #1 issues are sort of self generated classics (Action 1 is a classic, Batman or Superman 1 are typical #1 issues, no real artistic jazz) . The #24 is a top 10 in my opinion but pales in comparsion to the 14. I have always thought that classic covers were just that "Classic" There are awesome Horror, Torture, WWII Nazi books but Classic is a category in and of itself and 14 is by far the most classic of all.
For my money, classic covers are either fight scenes or almost artistic poses. I'm thinking of Captain midnight covers, Captain Marvel Jr and master Comics covers. Certain Frazetta Covers. Even typical DC or Marvel classics like Flash 123, certain Batman Bronze, Surfer 4, FF 25 & 112, Spiderman 39 50 etc.
Superman 14 is in a class by itself.