The beauty of someone's soul perhaps.
Physical attractiveness is helpful at the very beginning stages of a relationship but beauty doesn't last. People age and grow and that beauty fades.
If they are pretty on the outside but they are an awful mean person, then no it doesn't help.
I would rather take the person who isn't as pretty but is hilarious, honest, and respectful. That's the type of person I want to go grow old and compare wrinkles with.