I recently watched the first two for the first real time.
I love, but I don't know which is better. The first one felt much more like a full package, and the second was a bit more unfinished, but since its the middle part of a trilogy, I can let it off. Like The Two Towers.
Marlon Brando's absence is made up for with De Niro's inclusion though I think. He isn't as great, but he does it well.
What about the third? Is it a contender or not worth bothering with?