* "The Seven Year Itch" (1955): While this is one of her most iconic films, it's not clear if it was truly her favorite. It was a commercial success and cemented her image as a sex symbol, but she may have found the film's humor and subject matter somewhat shallow.
* "Niagara" (1953): This film, which explored themes of desire and betrayal, was considered a "turning point" in her career. It showed a darker side of her acting abilities.
* "Some Like It Hot" (1959): Though she had reservations about the film's script, Monroe reportedly enjoyed working with her co-stars Tony Curtis and Jack Lemmon, and the film became a major box office hit.
Ultimately, her personal preference remains unknown. It's likely she enjoyed a variety of films for different reasons, and her favorite could have changed over time.