Season one
Bauer didn't need much to get information from Ted Cofell: "You probably don't think that I can force this towel down your throat. But trust me, I can. All the way. Except I'd hold onto this one little bit at the end. When your stomach starts to digest it, I pull it out. Taking your stomach lining with it. For most people it would take about a week to die. It's very painful."
Season two
Known as one of Bauer's best kills — as well as spawning one of his cheesiest lines — Jack tapped his inner Arnold Schwarzenegger when he blew a Coral Snake mercenary away with a flare gun, telling him: "You're fired!"
Season two
Former militia member Marshall Goren came to a very messy demise despite being in the FBI's witness protection program. While he was being held in downtown Los Angeles, Jack first shot Goren, then went to extreme measures after deciding he needed his severed head to establish cover with a terrorist organization. "I'm gonna need a hacksaw," he growled.
Jack showed tremendous restraint (for him) by threatening to kill his wife's murderer just once during his interrogation of Nina, and not using the extreme action he's famous for. That's not for a lack of trying — the interrogation was stopped as soon as he laid a hand on her.
Season three
Even Bauer wasn't immune to the temptations of heroin when he went undercover with a gang run by Mexican drug lord Ramon Salazar. Jack took heroin to maintain his cover and got hooked, but going cold turkey to battle his addiction still didn't slow down his efforts to stop the sale of the Cordilla virus and keep daughter Kim (Elisha Cuthbert) out of danger.
Season three
In one of the most chilling moments of the season, Jack executed his boss, CTU director Ryan Chappelle, on the direction of the president to save the world from a deadly biological virus attack.
Season three
Infiltrating a prison was just the first challenge for Jack, who was then forced to play a few rounds of Russian roulette, first with a prison guard (he lost immediately) and then with Salazar. Not knowing whether the gun was loaded when it came to his turn, Bauer calmly pulled the trigger the first time and had a lucky escape, and on his second go he flipped the gun around and shot Peel, the prisoner who had forced him to play.
Season three
Bauer finally avenged his wife's death, with Nina trying until the very end to cause harm.
Season three
Jack used an axe to sever Chase's hand — and not because the man was his daughter's boyfriend. Chase heroically had strapped the final existing vile of the Cordilla Virus to himself, and Jack had to chop the hand to save Chase's life.
Season four
Being his girlfriend Audrey's ex-husband could have been motivation enough for Bauer to electrocute Paul Raines with a wire, and finding his name on the lease of a building used by terrorists was even more incentive (however, Paul went on to cooperate with Jack).
Season four
Breaking international law and countless CTU rules, Bauer went rogue and conducted a raid on a Chinese consulate to extract Lee Jong, whom he believed knew how to reprogram a nuclear detonator, resulting in a shootout that led to Paul Raines' death.
Season four
Jack took "enhanced interrogation" to new levels of gruesome when he shot terrorist Sherek in the kneecap.
Season five
Jack knew that Christopher Henderson (Peter Weller) would never break under torture, so he hoped shooting the man's wife would sway him. Jack was wrong.
Season five
Henderson managed to inject Tony (Carlos Bernard) with the deadly hyoscine-pentothal, and he died in Jack's arms before anything could be done.
Jack spent 20 months being tortured at the hands of Cheng Zhi in a Chinese camp in between seasons five and six — all because of a man who died during Bauer's invasion of the Chinese embassy in season four.
Season six
In his most painful kill yet, Jack shot Curtis for refusing to let terrorist Assad go. Assad had been pardoned by the president in exchange for information, but Curtis couldn't let go of an old wound – namely that Assad had overseen the slaughter of his squad in Iraq. Jack vomited in the grass after killing Curtis, a rare show of discomposure on his part.
Season six
Bauer family reunions are tough. Jack tortured his brother Graem by putting a plastic bag over his face, though in Jack's defense, Graem did try to kill Jack in season five.
24: Redemption
Jack was never more cuddly than when he saved a group of kids from some very bad men.
Season seven
Jack Bauer was called to answer for his sins, and he admits to torturing to protect innocent lives and says he is willing to have the U.S. people judge how he should answer for his actions.
"When I am activated, when I am brought into a situation, there is a reason. That reason is to complete the objectives of my mission at all costs."
Season seven
Jack is put in quarantine after risking himself by stopping a leaking bioweapon. He was weakened and nearly killed in the process, but was ultimately saved when Kim volunteered for a stem cell procedure.
Season eight
Just when it looked like Jack had a shot at happiness, Rene was gunned down — a move that caused Jack to become even more brutal than usual as he sought to finish out the 24 hours.
It's stuff like this that makes us understand why Jack is a wanted fugitive when we pick up with him in Live Another Day. The man took on president Charles Logan's motorcade, single handedly.
"Mr. President, get up or I will kill you right here," Jack said. But hey, Logan is a weasel and Jack had good reasons for doing what he did.
24: Live Another Day
In order to get away, Jack needed to cause a diversion in front of the U.S. embassy in London. His method of choice? Shooting two civilians in the leg to incite a riot and yelling "they're shooting at us!"
24: Live Another Day
Jack followed President Heller's orders to deliver the POTUS to terrorist Margot Al-Harazi. She shot him with a drone (or so it seemed), but luckily Jack had a trick up his sleeve that saved the president's life.