I was also watching Scarface which I've seen dozens of times but I've found myself disliking the ending. It's just too much of the Hollywood morality - the bad guy has to die at the end. The entire film is so much of a man-vs-man victory that to kill Tony at the end just seems to flaw the film. I have decided I prefer the ending of Scarface to be at the end of the dinner scene when his wife leaves him after he gives the 'Is this all there is?' speech. Cut to black. End.

The story of the sister and Manolo romance is a nice subplot, but it's alluded to in the Tony marriage scene where they make eyes at each other, and that's enough I think.

Tony is weird, weird for his sister, violent, controlling, but that point is made. Does it need to be made again? I think this is one reason GTA succeeded. It didn't force players into being 'the good guy'.