I've said before I think the first appearance of the Joker was a good story. The bronze age and later get some love. But what stories introducing recurring villains do you think shine in the '50s and '60s? Obviously, we have the new-at-the-time silver age heroes and their rogues galleries being introduced, but existing heroes got some new villains, too. I enjoy Heat Wave's first appearance, just for the budding bromance with Captain Cold.
