The Flash #179

The cover by Ross Andru and Mike Esposito poses a genuinely clever question: is the Flash real or just a comic book character? On the left, the Scarlet Speedster battles a swirling mass of colorful, jagged creatures in full action; on the right, a wide-eyed blond kid peers over the top of a Flash comic book showing that very same scene — and the bold tagline dares readers, "You Be the Judge!" It's a wonderfully playful bit of 1968 meta-storytelling that makes this issue hard to pass up.