Just rewatched this the other day. Yeah, this *may* be the Greatest Movie Ever Made. It's that good. For starters, it simply gets richer with every viewing. There are so many classic lines, including:
"I believe in America...."
"I'm gonna make him an offer he can't refuse."
"Leave the gun. Grab the canolis."
"Never discuss business at the dinner table."
"It's a sign. It means Lucca Brazze sleeps with the fishes." (my favorite)
"It's nothing personal, just business."
Individually these lines don't sound like anything special, but within their proper context they just have that right ring. Probably the most quotable dialogue since Casablanca.
I dunno. I used to think that Part Two was better, but it's so damn long and this one just seems to have the best pacing. And you have a character, Michael Corleone, who goes from a WWII hero courting a sweet schoolteacher and wanting nothing to do with the family business, to a cold-hearted killer and cut-throat businessman in just three hours - yet the transition doesn't seem rushed (in the movie, it's supposed to be over several years). Great work in that role by Al Pacino, one of THREE Best Supporting Actor nominees from the same movie.
Really, I can't find a single thing wrong with The Godfather.