With the release of Iron Man 3 just months away, Marvel fans are watching and re-watching the handful of Iron Man 3 trailers available on YouTube. And, if you’re like me, you’ve noticed the slow cadence of Ben Kingsley’s voice as the Mandarin. “Some people call me a terrorist,” he says, slowly and deliberately, “I consider myself a teacher. Lesson No. 1: Heroes. There is no such thing.” Then explosions and all hell breaks loose.

Kingsley’s voice as the Mandarin reminded me of the voice Tom Hardy used for Bane in The Dark Knight Rises. It, too, is slow and calculated. His voice is something between a purr and a growl when he says, “When Gotham is ashes, you have my permission to die.” Then, again, explosions and chaos.

This made me think: How many movie villains are defined, in some way, by their voice? There are, of course, some classic villains with classic voices, like James Earl Jones as Darth Vader. Dracula is another. Gary Oldman in Coppola’s Dracula and Richard Roxburgh in Van Helsing, among others, have given Dracula his Transylvanian tongue. And there’s Margaret Hamilton as the Wicked Witch of the West in the 1939 The Wizard of Oz. Her voice was part of the reason that I was too afraid to watch The Wizard of Oz as a kid. And as a pre-teen. And teen.

Some villain voices are more subtle, though equally menacing. Javier Bardem’s Anton Chigurh has a raspy, deep voice that fills every dialogue-heavy scene of No Country for Old Men. In Werner Herzog’s Aguirre: The Wrath of God, Klaus Kinski hisses Don Lope de Aguirre‘s lines in a sniveling, aggressive voice. And Malcolm McDowell’s portrayal of Alex in Stanley Kubrick’s A Clockwork Orange still occasionally gives me chills.

Hugo Weaving gave Agent Smith the perfect voice for The Matrix. “I’m going to enjoy watching you die, Mr. Anderson,” he says meticulously, like a programmer, scanning through lines of code. It is that voice that gave Neo something to fight against. When Smith breaks his composure, when his voice raises or his intonation changes, we know that something profound is happening. Like the Matrix collapsing. Or like Smith smashing plates of cookies.

Animated or CGI villains often have great voices, maybe because, on some level, they require great voices. Jeremy Irons as Scar is a classic example. Andy Serkis’s performance as Gollum is another good one. And Mark Hamill’s Joker is brilliant. Hamill plays the Joker for both Batman, the animated series, and the Batman: Arkham video games. (Hamill does other animated villain voices as well, including Red Skull, Solomon Grundy, and Hobgoblin.)

Maybe the most underrated yet iconic villain voice, however, is HALL 9000 from 2001: A Space Odyssey. Douglas Rain’s 1968 performance as the artificial intelligence is stunning. First, HALL 9000 is really just a light and a voice, so the voice is crucial to understanding the nature and villainy of the AI. But Rain went above and beyond, making “I’m sorry, Dave. I’m afraid I can’t do that” into a classic line of a classic scene of a classic movie. It is both intriguing and harrowing, and it is arguably the most memorable moment of the film. HALL 9000’s voice is also the voice I give to my duct-taped 1987 Ford Taurus when it decides not to start. “I’m sorry, Big B. I’m afraid I can’t do that.”