The Beatles, 'Tomorrow Never Knows' (Season 5, Episode 8)
Using the Fab Four's music doesn’t come cheap: The snippet from the trippy final track off of 1966's Revolver that closed out this episode cost a cool $250,000 to license. But the expense was worth it just for the image of Don, sitting in his swanky Lied Mobler recliner, attempting to understand what The Kids were into. Despite his dalliances with hippie women and pot, Don isn’t a fan of the swirling psychedelia-inspired track (which Lennon allegedly composed after tripping on acid) — he turns the track off midway through. And the fact that it's juxtaposed with Peggy and Stan smoking pot in the office is surely coincidental, right? Right.