I just watched it again today for the second time, and I was even more blown away than the first time I watched it. The movie shows in great detail every part of these guys' lives, whereas the Godfather, while also a flawless and brilliant movie (obviously), only shows about 10 years of time. Now if you put the Godfather parts 1 and 2 consecutively, it'd be better than OUATIA, but in a head to head comparison of The Godfather part 1 and Once Upon a Time in America, OUATIA wins IMO.