Is this really another DeNiro/Pacino thread?

Nah, I'm always up to discuss.

I personally consider Pacino the best, and my favorite role of his is as Michael Corleone in Godfather Pt II specifically, although I also really like him as Carlito Brigante just because it is probably the most different type of role you've seen him in as far as changing his actual speech patterns and mannerisms to fit that of a character.

I do really like DeNiro as well. I consider his best role to be Max Cady in Cape Fear, because again, it seems as though that's taking the most effort on his part because it is so far away from not only his actual demeanor, but also that of almost all the characters he's played over the years.