

I haven’t had a chance to read the whole comic yet, but this is getting a lot of buzz online: there was an old Carl Banks Uncle Scrooge comic in which the Beagle Brothers infiltrated Uncle Scrooge’s dreams, using some sort of apparatus invented by Gyro Gearloose, to get him to reveal the combination to his safe. Gyro, Donald, and the nephews show up but can’t wake Scrooge and the Beagle Brothers for fear of serious mental repercussions, so they send Donald into Scrooge’s dream.
Uncle Scrooge: The Dream of a Lifetime
(Thanks to Walter Smith and Matt Staggs)
Update: Commenter Your Obedient Serpent says this is comic was by Don Rosa, not Carl Barks, and it dates from 2002 – which is a lot less impressive.
From http://technoccult.net/archives/2010/08/05/inception-inspired-by-an-uncle-scrooge-comic/

Maze of Death by Philip K. Dick.
Inception seems to owe more than a little to Philip K. Dick’s reality-bending sci-fi yarns. In Maze of Death, which takes place in a world in which god seems to be an objectively real entity, several down-and-out misfits are assigned to work on a harsh, mostly uninhabited planet. But after losing radio contact with their employer they find themselves stranded without even knowing what their assignment is.

Japanese author Haruki Murakami is a master of writing surreal, dream-like novels. Hard-Boiled Wonderland and the End of the World revolves around a “calcutec,” who uses his brain as a type of encrypted storage. Companies hire him to store securely store trade secrets. Until, of course, something goes wrong.
Hard-Boiled Wonderland and the End of the World by Haruki Murakami

Neuromancer by William Gibson.
I thought of Inception initially as a Dickian film, but my friend Ian pointed out it’s actually more of a Gibsonian film. Neuromancer, Gibson’s first novel, is a heist story taking place in virtual reality. Inception fans should feel right at home.
From http://technoccult.net/archives/2010/07/30/inception-novels/