From Robin Williams' debut as Mork to the infamous 'jump the shark' moment, here are five essential episodes of Happy Days.

Happy Days was one of the most successful sitcoms of the 20th century — the ’50s-set family comedy ran for 11 seasons, yielded seven spin-offs, jumpstarted the careers of Robin Williams and Henry ...

We may receive a commission on purchases made from links. Originally aired beginning in 1974 -- just one year after "American Graffiti" put George Lucas on the map and made the 1950s cool again -- ...