While Pacino is a good actor, Marlon Brando is far superior. He is the one always emulated by actors today, although Pacino and Deniro are more popular b/c of the size of their work.

With Brando out of the picture [literaly] who is the greatest living actor now between the two? It's like comparing apples and oranges --->

Pacino has perfected going where the character takes him. He has become so emotional caught up in certain performances he has often times been rushed to the hospital after the shoot due to exhaustion. One example is in GFII when he learns Fredo has betrayed him. He collapsed and was sent for medical treatment. This has happened more than once. --->

On the other hand, Deniro is a minimalist; not a bad quality, b/c it seems to work hands down. For him, less is more.

You simply cannot compare the two. It's a loaded question. And for that you get an orange.