The 25th anniversary Commemorative Edition (only 6,500 made) ever released on DVD or Blu-Ray is the only way to see the complete trilogy in chronological order with missing scenes and a documentary “The Godfather: A Look Inside” added.
I re-watched all 9 hrs., 43 mins. of this over a two day period and must say that it is a unique experience which makes all the recurring motifs and family themes more obvious.
TIME magazine wrote: “This trilogy has a novelistic density, a rueful, unhurried lyricism and a depth that, singly, the films could not achieve. Altogether glorious.”
Highly recommended, especially for Godfather, Coppola, and serious film-making fans if you are able to buy it from an online seller.