I do believe I had every hero and villain shown in this video and many more.  They came in rectangular cardboard boxes; about half the size of a Kleenex box. At the store they were stacked on top of each other. It was fun tearing apart the toy aisle to see what each box contained.

Besides super heroes and their respective villains, I had characters from other series: Wizard of Oz, Star Trek, Planet of the Apes, Starsky and Hutch, Welcome Back Kotter, Archie Andrews and Jughead, The Rookies. And oh so many more!