Thank you so much for the suggestions for my presentation! I have selected about 10 scenes now which is way too much since I'm only planning on using about two. I've narrowed it down to: The Carousel, Betty & Glenn in the car, Joan & Don bond in the restaurant, the scene with Joan & Peggy from season four reacting to Don's engagement and Peggy telling Pete she had his baby.
Out of the ones you mentioned, I really love Peggy telling Pete she had his baby and Betty and Glenn in the car! The Carousel is a classic too.