Here's what we know:
* She was a fan of the popular music of her time. This included artists like Frank Sinatra, Dean Martin, Ella Fitzgerald, and Nat King Cole, who were all major stars in the 1950s.
* She enjoyed jazz and blues. There are accounts of her attending jazz clubs in New York and Los Angeles, and she was known to be a fan of Billie Holiday.
* She was a fan of classical music. Her friend and photographer, Milton Greene, once mentioned that she enjoyed listening to Chopin and Bach.
* She had a love for musicals. This is evident in her performances in films like "Gentlemen Prefer Blondes" and "There's No Business Like Show Business."
Unfortunately, there isn't a concrete list of her "favorites" as she never publicly declared them. However, based on the music that was popular during her lifetime and her own personal taste, we can assume she enjoyed a variety of genres, including jazz, blues, classical, and popular music of the 1950s.
If you're interested in exploring the music Marilyn might have enjoyed, listening to artists from the era mentioned above is a good starting point. You can also find recordings of her singing, which showcase her musical preferences.