While I’ve seen Godfather I and II scores of times, I can barely remember Godfather III.
I only remember it being rather plodding, and a lot of people not liking it. Its certainly never on TV like the first two.
Godfather I and II were based on the book. Godfather III was not, and was a mess.
I remember Godfather marathons on Thanksgiving that only played 1 and 2.
I still don't completely understand the plot of III and I've watched it a few times. I usually lose interest and the movie ends up watching me.