What's your favorite fictional depiction of Satan?

This one.

The devil in that old Twilight Zone episode, who was kept in a monastery cell, until a visitor freed him. That sequence of him transforming as he walks behind the columns . . . gives me chills no matter how many times I see it. Great editing!

Harvey Keitel in Little Nicky. Yes, I liked Little Nicky. Yes, I know I’m a horrible person.

that episode was called…

…“Printer’s Devil”

In Drive Angry, Satan never appears on-camera, but this quote from the Accountant stuck with me:

And in case anyone is unaware, a printer’s devil is an apprentice printer used as a gofer.

There was an episode of “Northern Exposure” where the the devil attempts to get Shelly to do something (I can’t remember what) to/for Holling. And the devil was played by Charles Martin Smith (Toad from “American Graffiti” and “Never Cry Wolf”).
I have always thought this was one of the better portrayals: the devil would be conniving and smart - so to show up with horns and flames would be “too” obvious.
Elizabeth Hurley and Robert DeNiro are somewhat disguised, but still a bit “showy” (Louis Cypher’s manicure, for example).

Charles Martin Smith was just “joe ordinary” camping on the side of the road. Nothing threatening or intimidating at all !

Literary: Heinlein’s Job, a Comedy of Justice.
“Is this Hell, or is it Texas?”
“What’s the difference?”

Cinematic: Al Pacino in The Devil’s Advocate.
“I never made anyone do anything they didn’t want to do. Free will. It is a bitch.”

Stephen Vincent Benet’s “The Devil and Daniel Webster”.