22. "At The Codfish Ball" (Season 5, Episode 7)
Megan's parents visit New York to attend a banquet honoring Don, which means we meet Julia Ormond as the femme fatale Marie Calvet — c'est magnifique. Don wins an award that turns out to be as meaningless as every other prize on his shelf. And poor Sally, dressed up like Edie Sedgwick at the Factory, has a dinner date with yet another dashing father figure who disappears and lets her down. Go get 'em, tiger.
Best line: "Men don't take the time to end things. They ignore you until you insist on a declaration of hate."—Joan Holloway Harris