I am addicted to 24 and to Jack Bauer! I've seen the first three seasons on dvd by borrowing them from my local library. Here are synopsis of the first three seasons:

Season 1 begins and ends at 12:00 AM on a Tuesday, and occurs on the day of the California presidential primary. Jack Bauer must protect Senator David Palmer from an assassination plot, and rescue his family from those responsible for the plot, who seek retribution for Jack's involvement with a covert U.S. mission in the Balkans.
Set 18 months after season 1, season 2 begins and ends at 8:00 AM. Jack must stop a nuclear bomb from detonating in Los Angeles, then assist President David Palmer in proving who is responsible for the threat.
Set 3 years after season 2, season 3 begins and ends at 1:00 PM. While struggling with heroin addiction, Jack must re-infiltrate a Mexican drug cartel in order to keep it from acquiring a deadly virus. Jack must then stop the mastermind behind the virus from releasing it.
