On November 8, 1972, Home Box Office began transmitting its service to 365 Service Electric Cable TV subscribers in Wilkes-Barre, PA. Its first program? A National Hockey League game from Madison Square Garden, followed by an airing of the feature film Sometimes a Great Nation. The following year, the first championship boxing match (George Foreman vs. Joe Frazier) and the first original, pay-TV entertainment special (Pennsylvania Polka Festival from the Allentown Fairgrounds, dontcha know) aired on HBO.

HBO's come a long way in the past 45 years, and to celebrate, the premium content channel is celebrating its storied past by discovering or revisiting several legendary series, whose pilot episodes are available to watch for free on HBO.comThe WireSix Feet Under, Big Little Lies, The Sopranos, True Blood, Westworld and Game of Thrones.

Of course, subscribers can watch these series in their entirety whenever they like via HBO GO or HBO NOW, where they'll find a different iconic series being highlighted each week between now and the end of the year.