3. Alan York
This early day one twist set the tone for the level and complexity of the surprises the show was capable of. Jacks daughter, Kim, is a typical teenager who snuck out to spend the evening with friends. Her worried mother and Alan York, the father of Janet, a girl who went missing with Kim, head out to find them and make sure they are safe. Janet gets involved in a road accident and the parents find her at a local hospital. Her father asks the doctor to allow him some time alone in the ward to check on his little girl. Stirring from sleep Janet doesnt recognise him. Chillingly, he suffocates her and turns off the machine monitoring her. For five hours we had followed these worried parents only to discover that Alan York had been murdered before the series had even begun and the man posing as him, Kevin Carroll, was involved in a plot to kidnap the family of Jack Bauer. A fantastic twist made better by being impossible to guess until it was too late.