Pacino just edges because of Scarface, Carlitos way, Heat, The Godfather trilogy and Donnie Brasco.
But DeNiro is in my favourtie movie of all time Goodfellas, then of course there's Taxi Driver, Raging Bull, Heat and The Godfather part 2.
Damn its a hard question
But Pacino just wins because of DeNiro taking the parts in Showtime and Rocky and Bullwinkle, what the hell were you thinking Rob?