15. "Out Of Town" (Season 3, Episode 1)
Limit your exposure, indeed. Don and Sal take a business trip to Baltimore, where they find very different kinds of romantic adventure. Don gives Sal a lesson in the hobo code, as they spend a night pretending to be FBI agents. ("You ever heard of James Hoffa?") He also brings a souvenir home for his daughter — a stickpin from the uniform of the stewardess he just bedded. Don Draper, father of the year.
Best line: "Help yourself. Not the Stoli."—Roger Sterling to Pete Campbell