In 1998, when Armageddon was released, Bruce Willis was one of the biggest stars around, and Armageddon acknowledges this by nodding to a couple of the actor's other films. At one point, while Max (Ken Campbell) is undergoing his NASA physical, he looks at the gigantic syringe being wielded by a doctor and tells him, "You stick that in me, I'm gonna stab you in the heart with it." Then, to make the reference crystal clear, he says, "You ever see Pulp Fiction?"
This refers to the 1994 Quentin Tarantino film Pulp Fiction, specifically the scene in which Vincent Vega (John Travolta) revives Mia Wallace (Uma Thurman) following a drug overdose by sticking her in the chest with a large hypodermic needle. Pulp Fiction also starred Bruce Willis as Butch Coolidge, an aging boxer who winds up an unwitting murderer, meaning that somewhere in the world of Armageddon, Bruce Willis exists alongside Harry Stamper.
Also, while it's not as obvious of a reference since the film isn't explicitly named, one of the NASA pilots in Armageddon is named "Gruber." This could just be a coincidence, or it could be a reference to Hans Gruber, the villain from Die Hard, who was played by Alan Rickman.
