What a great list!! I would add a few personal favorites of mine, some of which have already been mentioned:
1968 US Nationals - Peggy Fleming. She herself has said this was her best competitive performance, and it sure was magnificent. She flowed across the ice, landed all of her jumps, and looked every bit the future Olympic champion, which she was.
1970 US Nationals - Janet Lynn. Janet delivered several memorable competitive performances, including this one. Her 1972 Olympic long program included a fall from a flying sit spin, which she recovered from quickly, with a beautiful smile.
1976 Olympic long program - Dorothy Hamill. Just loved her "American beauty rose" costume and her skating. She was strong, powerful, landed all of her jumps with ease and confidence. It was so great to see this girl put it together and show the world how great a skater she is.
1982 US Nationals - Rosalyn Sumners skated beautifully and defeated Elaine Zayak, who had a very poor outing. Sumners was another powerful, graceful skater.
1984 Olympics - Katarina Witt's "Gershwin" long program. Loved her rose costume and her skating. She was beautiful, and she skated with power and confidence. IMHO, she was one of the best champions of all time.
1989 Worlds - Midori Ito skated brilliantly, landing the first-ever triple axel by a woman, and brought down the house in Paris. Great, great skating. Ito had also improved her artistry, so she was not just (?!) a jumper, but a great all-around skater.