There are very few plants that I see at shows that I remember in detail, but Den speciosioum v. hillii 'Don Brown' CCM/AOS is one... very early in my orchid career, I went to the Santa Barbara show and saw this beast...(AOS award description)
"A truly majestic, magnificent specimen plant two meters tall, three meters wide with approximately 100,000 flowers and 173 buds on 400 inflorescences displayed in a symmetrical sphere; flowers cream white; lip maroon stippled."
I had just purchased a fairly small Den. speciosum at an earlier show, and thought, 'OMG, I just bought a St. Bernard puppy!" Fortunately or unfortunately, I don't grow these quite so well...