Two set reveals from the '80s still stick in my head: Tony Walton's Act Two set for A Day in Hollywood/A Night in the Ukraine and Clarke Dunham's backstage set for Grind.
Hollywood/Ukraine had two different sets for the two acts. Act One, set at Grauman's Chinese Theater, was fairly simple... basically a series of five lobby doors, painted black on one side, red on the other, forming different patterns throughout the show. When the curtain went up on the Act Two set, there was a collective gasp of wonder in the audience. The Act Two set was a Russian mansion in an eye-piercing shade of blood red and gold, with shiny black floors. Really a stunning moment.
The Grind set was, as I recall, first revealed after the opening number. You were outside Harry Earle's Burlesque house, but the set had four or five pieces on revolve, and the set spun around to reveal the entire backstage of the burlesque house, all at once, as if you had taken an entire wall off the building and could see everything going on in each room at the same time.
Begin at the beginning and go on till you come to the end: then stop.