Batman #166

From September 1964 comes this thrilling DC issue featuring "Two-Way Deathtrap!" — and the cover by Carmine Infantino and Joe Giella makes the peril immediately vivid. Batman is submerged in churning, bubble-filled water while a missile or dart streaks at him from both sides simultaneously, the waterfall and rocky cavern walls hemming him in with nowhere to escape. It's the kind of split-second, no-good-options scenario that made Silver Age Batman covers so genuinely hard to put down.