Francis Bacon
I never cared for portraits until I saw those made by Francis Bacon. He had an amazing skill at transforming the human anatomy into a surreal mess of meat. Bit of trivia, in Tim Burton's first Batman film, there's a scene where the Joker tells his henchmen not to destroy a Bacon painting.

Luigi Serafini And The Codex Seraphinianvs
Serafini is an Italian graphic designer and architect who created a legendary book in the 1970's. It is of a completely fictional world with illustrations depicting peculiar lifeforms and a varied selection of other details addressing this imaginary world. It is written in a non existant language. It goes so far as to depict a rosetta stone which merely translates the text into another non existant language. If you're interested in hunting down this mysterious book, it apparently fetches 200 - 250 dollars at various internet book stores. For additional information on the book and the artist, check the links below.

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11 pages from the codex
Codex Seraphinianus, Hallucinatory Encyclopedia
Official website of Serafini with a few bizarre images and animation.

Wes Benscoter
I've been a fan of Benscoter for 9 years now. His airbrush paintings are always filled with strange demons and other morbid characters. To see some of his art in print check out the fantastic art anthology Spectrum.

Zalibarek
Yet more proof that Poland is an amazing source of fantastic artists. The imagery resembles fragments of unusual dreams. Bodies, furniture and buildings are combined together in a perpetual wasteland of oddities.

Chris Ryniak
Chris has made a crazy assortment of cartoon like characters fit into detailed paintings. Each image feels like a scene from a very bizarre cartoon that I'd like to see. There is an emphasis on individual characters expressing themselves through text, icons or objects.