7. "Seven Twenty Three" (Season 3, Episode 7)
If you're a Bert Cooper fan, you're a fan of this episode — the old man demands Don's signature on a contract, unveiling the ruthless glare behind his genial smile. There's so much we never find out about Bert, a more bloodthirsty badass than Don or Roger will ever be. (When will we see his groovy sister Alice again?) But the sinister side of Bert "Beware the Non-Conformist" Cooper emerges when he wants something — like one of those moments in The Godfather when the aging Vito Corleone reminds everyone he's still the Don around here. The climax has to be the scariest Scary Bert scene ever.
Best song: Tennessee Ernie Ford's "Sixteen Tons," about the perils of owing your soul to the company store.
Best line: "Would you say I know something about you, Don?"—Bert Cooper