Turns out, Jack's brother and father weren't exactly as heroic as their sibling and their son.

Played by Jon Voight, Jonas Hodges was an executive at Starkwood on Day 7. He was intent on using missles to destroy U.S. cities unless the President hired his firm as her primary military contractor.

Habib Marwan dared to kidnap James Heller and Audrey Raines. He also bombed Air Force One on Day 4.

A former MI6 agent, Stephen Saunders was tortured for years and then sought revenge by trying to release the Cordilla virus in the U.S.

Revealed as the terrorist behind a group called Second Wave, Syed Ali coordinated the transfer of a nuclear weapon to Los Angeles.

Your ideal, crazy villain, portrayed by the mesmerizing Dennis Hopper.

A First Lady always seeking the upper hand, Sherry Palmer covered up a pair of murders and worked to overthrow her husband's administration.

The Season 1 turn of Nina Myers proved that 24 would go where few other shows have ever gone.

One of the most memorable Presidents in TV history, Logan went from a bumbling Commander-in-Chief to the mastermind behind the sale of nerve gas... and the assassination of David Palmer.