Nick and Nora Charles became an iconic couple when "The Thin Man" (1934) became a huge hit during the Depression as their carefree, fun loving attitude really connected to audiences looking for escapism.
The monster success of the film led to 4 follow up "sequels" and Willliam Powell and Myrna Loy became huge stars. Loy was often referred to as the "Queen of Hollywood" at the height of her career. Her voice is unforgettable. Even the Charles' dog Asta became a star!
Here's some background on the series from AMC's Filmsite:
The Timelessness of the Series
James Bond had nothing on Nick and Nora's Martini Binges
The Trailer and Some Great Scenes
Here's some the best lines in the movie:
And here's the original preview. It starts off a bit strange, but then goes into a more normal trailer presentation.