To answer my own question, maybe 'it' was the characters? I think the fun of watching these movies is there is a clear side to root for, and the fact that Luke, Leia, and Han are underdogs makes it even more satisfying in the end. I think we all got spoiled in these characters cause they were that perfect for their roles. They had the perfect chemistry, they played off each other so well, it was like we actually knew these characters.

For many of us, including myself, Star Wars '77 was our first movie experience, and I absolutely loved it, so at 5 years old where do I go from there? OK, now I see an awesome sequel to my favorite movie, where do I go from there? OK, I see a very good sequel to end the trilogy, OK where do I go from there? Through the course of everyone's life, we will all have a favorite movie we will see and love before we die, for many of us we saw ours before we were 10 years old! We hit the mountain top so early in our life, maybe there was nothing that was going to top it.

I guess why 'it' works so well is, think about when Luke, Chewy, and Han first rescue Princess Leia in the deathstar, and they starting shooting at the stormtroopers, and within seconds they are all arguing: Leia, "Great plan, did you have a way to get us out?" Han, "He's the brains sweetheart!" I think that is tough thing to pull off when characters first meet each other cause dialogue like that could come off as forced to try to get a laugh, but for some reason even though Leia has just met Han & Luke, I think her barking at them, and saying she is in charge, is one of the great exchanges that many movies miss.