I wonder why there's so much Shawshank love here. It was a well made movie, although very slow-paced. Ditto The Green Mile, another prison story from Stephen King.
My vote went to Godfather, although I agree with Gunman the third movie brought down the quality of the series. Sofia Coppola wasn't a good actress, but she didn't bring down the movie by herself; the whole thing was a cynical attempt to milk the series for more cash. The storytelling was lackluster, and the fun and interesting original characters were mostly dead or missing from GF III. Blah! The real Godfather story, as told by Mario Puzo, ended with GF II. I LOVE the book; I am one with Fredo the Weak One.
I'm surprised you ghey boys haven't noticed Midnight Cowboy is missing from the list. It's in my top 10.