For Lois's birthday, Superman gave her powers like his temporarily; he took her along for some crime fighting; he solved the riddle of the unstoppable force and the immovable object to save her; he defeated Samson and Atlas at arm-wrestling simultaneously to "win" her affection; he took her to dinner in Atlantis, then finished up by making out with her on the Moon. All in one day, one issue.
The riddle scene alone is its own Crowning Moment of Awesome:
Ultra-Sphinx:Question: What. Happens. When. The. Unstoppable. Force. Meets. The. Immovable. Object? Superman:How about this? They surrender. Ultra-Sphinx:Response. Acceptable.
A young Superman takes on his counterpart from the future:
Kal Kent: I'm faster! Stronger! Able to leap from world to world in a single bound! ...Your solar powers are in their infancy! You're not as strong, as smart or as fast as you will be... Superman: Oh, yeah? But I have my dog!
Luthor gets a fitting, if somewhat inauspicious one in issue 10: when Superman visits him in prison and issues the 'save the world while you still have time' bit, Luthor simply walks up to the glass and spits on it and gives Supes an A-level Death Glare. 70 years of continuity and rivalry boiled down to one hocked lugie and two implacable foes.
ALL of issue 10 qualifies.
This may be more a personal one, but my respect for All-Star Jimmy shot up tenfold when he swung a punch at Super Luthor. It didn't do jack, but still.
In his Day In The Lime Light issue, he gets a few but the best are beating an out of control Superman by becoming Doomsday and arranging to have "I Love Lucy" carved into the moon for his date with Lucy Lane.
When Jor-El tells Kal that he's dead and being converted to living solar consciousness, he states, "You can stay and play in the fields of consciousness. Or you can turn and face evil one last time." Guess what he chooses?
Meta, but in issue six, Funeral in Smallville, when the Unknown Superman removes his bandage-disguise to reveal our Superman, he turns around and sees the golden Superman, the Prime Superman, of DC One Million exiting deep time. our Superman asks the Prime Superman, "which of my descendants are you?" Prime Superman just chuckles: he knows exactly who our Superman is.