One Perfect Moment: Batman / Deadman
From Detective Comics #500, by Cary Bates and Carmine Infantino. Batman has been poisoned, and is lying in a hospital bed on the brink of death. Luckily, Deadman is on the scene, and heads to the Astral Plane to lend Bruce's soul some moral support. But there's a problem:
Deadman's smile in that last panel just slays me, every time.