I've watched FFVII: Advent Children 3x and I still don't get the story. In fact, I did understand the whole storyline until I played the above game. Man! Did it change EVERYTHING! I wasn't playing a game...I was living in it. The character, storyline, universe, NPCs and the ending just drew me in, even emotionally. I won't spoil anything but this is one of those rare moments that I shed a tear at the end. I'm playing it again on HARD mode, watched FFVII:AC again and this time I not only understand the entire story but I appreciate the characters and universe even more so.
Here's a picture tribute to Zack and his love, Aerith...