Hard to choose, so I'll say all of the above. Can't say how many times I've watched Oliver!. Probably in triple digits by now.
I'd say post WWII to 1970's was the golden age. 1920's and 30's musicals never appealed to me much, even when the songs and music were good. They had a pretentious and cheesy sophistication, too many tuxedos, cigarette holders and champagne* glasses for my taste. In the late 1940's musicals came down to Earth, which is where I live.
The only DVD's I buy are film musicals because I know I will keep going back to them and they wont just sit there and gather dust on my shelf.
To the above I'd like to add:
The Music Man
On The Town
Gypsy
Sweet Charity (they shot two endings for this movie. I think opting for the sad ending was the right call, it was devastating, I cried like a baby)
Would this be considered a guilty pleasure in a classical music forum? - If so, I'm guilty. I mean not guilty.
*I've got nothing against champagne, a good champagne buzz is a thing to behold.
Best wishes
Metairie Road