Musical is also my least favorite. If THE MEANING OF LIFE only has a few musical numbers, so I'm not sure if it counts - Every Sperm is Sacred, the galaxy song, etc. If it has to be a pure musical, then maybe THE SOUND OF MUSIC. I refuse to watch LA LA LAND, CHICAGO, MULAN ROUGE, etc., so I can't tell you if they were good or not.
As a child, I would watch Disney, and other movies of that type. I would be so into the story and the fantasy, then all of a sudden they would break into a song. It was like breaking the fourth wall, because I was believing the movie up to that point. You just "stopped" a good story in its tracks! The movie became theater.
I don't know if I have a 2nd least favorite. I've really started to appreciate dramas and romances in my rape old age. I like young adult. I'm a sucker for all the TWILIGHT films. I like westerns, too. War films are fairly interesting. Thrillers, action, mystery, horror, sci-fi..... I love em all!