Mine had to be the final panal of Amazing Spider-man #39 (1966) where a totally defeated Peter Parker sits mechanically tethered and defeated with his ripped 'civies' revealing his Spider-Man costume while the Green Goblin reveals himself to be Norman Osborn! A heart-stopper for me at 14 years of age because this kind of thing had NEVER happened before "for real" in any comic book I had ever read!

Sure, there had been convoluted identity reveals in Batman and Superman in the 50's and 60's but they had been "imaginary stories" or very phony premises with even phonier explanations and outcomes. Spidey #39 was "THE REAL DEAL" and the reader knew that ALL HELL was going to break loose in the following issue!

It was the longest month of my life waiting for issue #40 to hit the newstand, and you'd better believe that I was at Nugent's Drug Store with twelve cents in my hot little hand to buy it on the day it arrived!