Welcome to main event, Dirty Harry versus John McClane. You absolutely cannot go wrong with any vote here.
Before we get to the voting, weigh the bodies of works of both these gentlemen (and, don't necessarily hold Willis' age against him - Clint had a 20 year head start)
Bruce Willis: Die Hard, Die Harder, Live Free or Die Hard, Billy Bathgate, Last Boy Scout, Die Hard: With a Vengeance, 12 Monkeys, Last Man Standing, The Jackal, Armageddon, Fifth Element, Mercury Rising, The Siege, Unbreakable, Tears of the Sun, Hostage, Sin City, Grindhouse, Surrogates, The Expendables, Setup, Red, Catch .44, Looper, Expendables 2, A Good Day to Die Hard, Vice, The Prince, Red 2, etc.
Clint Eastwood: Dirty Harry, Unforgiven, Gran Torino, The Outlaw Josey Wales, High Plains Drifter, The Good, the Bad, The Ugly, Pale Rider, Fistful of Dollars, For a Few Dollars More, Escape From Alcatraz, Sudden Impact, Dead Pool, The Enforcer, Where Eagles Dare, Two Mules For Sister Sara, Tight Rope, Paint Your Wagon, Hang 'Em High, The Gauntlet, Magnum Force. Heartbreak Ridge etc.