Yes, the "Saga" version is the definitive treatment of GF and II, chronologically ordered and with ~75 minutes of deleted scenes (every one of them great) in the right place. I bought my first VCR specifically to record the Saga, practically wore out my tapes playing it over and over again.

HBO released the Trilogy in chronological order, with deleted scenes, several years ago. I liked seeing it in hi-def and I made Blu-Ray discs of that version. But, the Saga still is the best for GF and II. Here's an example you may have noticed:

On the HBO version, and on the "Extras" disc in the DVD set, the deleted scene where Gardiner Shaw asks Michael for Sonny's daughter Francesca's hand in marriage ends with Michael shaking Gardiner's hand. But the Saga version has about 10 more seconds at the end. Michael turns to a hulking young man wearing a plaid sport coat and says, "How's the football, Santino?" "Fine, Uncle Michael," the lad replies. Santino would be Sonny's first son--his second son, Frank, is seen in GF reading a get-well card to Vito when he returns from the hospital. Small but interesting addition to Sonny's family.