I voted for "Guess..." because its a work of art ahead of its time. It is one of my favorite movies not necessarily due to the acting, story, location, stars, etc. It just has the ability to let you see each character process their dilemma in a very real way. It's a nice period piece, too. And seriously, the drama surrounding this film also helps with the allure as well (Last Hepburn-Tracy film, black-listed director, black rights issues across the country, etc.).
Anyway, I'd love to read your take on it. Like I said, it's one of my favorites.