10. "My Old Kentucky Home" (Season 3, Episode 3)
Hunter S. Thompson was right — the Kentucky Derby is decadent and depraved, at least when it involves Roger Sterling singing in blackface. Roger makes an ass of himself at his posh Derby Day soiree, but he isn't alone — over the course of a May weekend, everybody keeps giving musical performances that secretly reveal all their hidden emotional turmoil. (Just like the "Sirens" chapter of Ulysses.) Paul sings a stoned duet with his old pot-dealer pal from the Princeton Tigertones. Pete and Trudy do the Charleston. And Joan plays "C'est Magnifique" on the accordion for dinner guests, putting up a brave face even though she's just figured out her marriage is even more of a fraud than she realized.
Best line: "My name is Peggy Olson and I want to smoke some marijuana."—Peggy Olson