I'm rereading the Godfather Legacy book, and wished DeNiro had played Sonny. I've never been a big fan of James Caan in the part.

I guess in DeNiro's screen test he came off a little too crazy, but, he certainly has the intensity to have made Sonny a much more interesting character than Caan did.

One big drawback is who would've played young Vito in part 2?