Although Hollywood didn't touch on all the aspects of their lives, I think the real life relationship of John Nash and Alicia Larde is an excellent example of a marriage going the distance! As for the movie (Beautiful Mind) I always get a kick out of Nash's proposal to Alicia, and her response!

My name is Oedi and I soar amidst the stars far from the planet of my birth. I guess this starship is the closest thing I've got to a home now, for I am a refugee and an outlaw. Vanth Dreadstar, Syzygy Darklock, Willow 327, Rainbow and Skeevo are my family. We are revolutionaries. Our goal? To bring an end to the 200 year old war between the Instrumentality and the Monarchy!