6. Alan Kalter
With his bold, slightly self-mocking voice, announcer Bill Wendell was instrumental in establishing the brash, snarky tone of Late Night — still, the man who replaced Wendell after his retirement would ended up becoming a more central figure. Joining the Late Show in 1995, Alan Kalter wasn't simply the guy who introduced Letterman every night. With his stentorian voice and stiff demeanor, Kalter seemed like Central Casting's idea of an old-school radio broadcaster, which only made his bits that much more off-the-wall and fun. Kalter escaping the Ed Sullivan Theater, Shawshank Redemption-style, is an all-time highlight, but we really love "Alan Kalter's Celebrity Interview" in which the big name he'd booked for the segment was the exact same star Letterman had just interviewed on the show. That would set the announcer off into a rage spiral; anybody can say, "Bite my junk, suck-rod," but only Kalter could make it so consistently hilarious.