Here is a list of the best musical movies to watch on Amazon. I updated the list with recently released "Hamilton" and "La La Land". My favorite ones are: "La La Land" and "Singin` in the Rain". Check them out if have not seen them already, otherwise, I am sure you will find something new.
Also here are the best movies of all time and genres. Or if you like the other genres feel free to check out my other lists of the best action, adventure, animation, comedy, crime, drama, family, romance, sci-fi, thriller, or western movies that are worth watching.