If you've never seen "Guess Who's Coming To Dinner", you should.  It's a really amazing look at racial tension in the 60's.  It's also the last movie Spencer Tracy ever made.  He and Katherine Hepburn were one of the greatest love stories, like, EVER! 

And if you jump to about 4:30 in this admittedly long clip, you'll see why I love this movie.  Tracy died a few weeks after filming this movie, and the way he looks at Katherine Hepburn is heartbreaking.  He was ill and they both knew that he didn't have long, and to see that look of "I've loved you for so long and will go on loving you even when I'm gone" in his eyes, well!  I can't get through this scene without bawling my eyes out!  Because they were so in love in real life and got to put that love on film before he passed away, that's why I think this is the most romantic movie moment EVER!