In the 1964 film My Fair Lady, directed by George Cukor and based on the 1956 play by Alan J. Lerner, both based on George Bernard Shaw's 1913 Pygmalion, Eliza Doolittle (Audrey Hepburn) must chose whether or not she will return to Henry Higgins (Rex Harrison). Anyone who has seen the musical knows that she does indeed return to him in the end, and in my experience the general consensus is negative towards that outcome. I, however, feel that this is the best possible resolution.
Higgins gives Eliza a priceless opportunity to break out of her downtrodden low-class position in life and be respected as a "lady" by reforming her mannerisms and her speech. The problem comes after her transformation is complete, and she realizes she no longer fits anywhere. She cannot return to the other side of the tracks and sell flowers because she is no longer even recognized there. She has no means and ways of living without some type of profession or benefactor either. She does, however, acquire the love of the socialite Freddie (Jeremy Brett ), but that too is a dead-end road. She cannot exactly run to her father (Stanley Holloway) either because he makes it quite clear that he does not want to provide for her even after he has the means to do so. Freddie can offer her no real financial support or stability; and one cannot live on love alone, despite the beauty of that idea in theory. Furthermore, Eliza never mentions returning Freddie's affections, and I do not believe that she is in love with him.
Higgins does not intend to marry Eliza, but she does offer him companionship, and they do possess an affinity for one another. The only real problem with Henry and Eliza's relationship was his taking her for granted. Eliza solves this problem by proving to Higgins that she can walk away and that her absence is unsettling.
Higgins is well off and can provide support and stability for Eliza. Although Eliza has proven in the past that she can be self-sufficient, one wants to see her taken care and not have to struggle to make a living. Returning to Higgins is the most logical option for Eliza.