What do you think is the most evil you computer you have ever seen (or heard of) in movies or otherwise....?

Colossus in "Colossus: The Forbin Project"

Colossus and Guardian (Soviet equivalent of Colossus) link together to rule the world!

http://www.imdb.com/title/tt0064177/

There is a series of three novels by D.F. Jones about Colossus' rise and fall then what comes after:

Colossus

The Fall of Colossus

Colossus and the Crab

The runnerup would be Proteus in "Demon Seed", who managed to impregnate a woman to bear "his" offspring: Proteus in human form.

http://www.imdb.com/title/tt0075931/

I agree that Skynet is a baddie, but we directly experience the two above.

***HAL SPOILER***

HAL wasn't really evil or a villain. Tthe things he did were because they had contradicted his programming, telling him to lie, as is revealed in "2010".

My first thought was HAL in Space Odyssey. But since you mentioned that one, how about looking at this film's evil computer program: "Avalon." This film was made in 2001.

Edgar, from Electric Dreams

Master Control, from Tron.

Skynet.

AOL