Great musical BUT...
....not as powerful as the 1938 classic Pygmalion.
If you watch Pygmalion which has almost the exact same dialogue based on the Shaw play, you'll notice a much more powerful performance by the lead actors. My Fair Lady is overall a colorful and entertaining experience being a musical and having Audrey Hepburn and Rex Harrison in the lead which obviously makes it a great movie. Pygmalion is stripped of color and songs and instead the pure story.
I realized that if you watch Pygmalion, it kind of ruins My Fair Lady for you because the first is so much more powerful.