Good question, Meghan. How are you? I take it that you mean to include the roles other than U.S. presidents? I would say Morgan Freeman as Mandela in INVICTUS. Dennis Haysbert in the TV series 24 (also in the ALLSTATE insurance commercial), Harrison Ford in AIR FORCE ONE, Jon Voight as Roosevelt in Pearl Harbor and Gene Hackman as the villanous president in ABSOLUTE POWER.