Top 20 Countdown: Most Shocking (2009-2012)

48 Hours is a CBS news magazine that investigates intriguing crime and justice cases that touch on all aspects of the human experience. Over its long run, the show has helped exonerate wrongly convicted people, driven the reopening -- and resolution -- of cold cases, and changed numerous lives. CBS News correspondents offer an in-depth look into each story, with the emphasis on solving the mystery at its heart. The program and its team have earned critical acclaim, including 20 Emmys and three Peabody Awards.

Earth is visited by an alien species that threatens humanity's existence. Events unfold in real time through the eyes of five ordinary people across the globe as they struggle to make sense of the chaos unraveling around them.

Smart, sarcastic and a little dead inside, Wednesday Addams investigates a murder spree while making new friends — and foes — at Nevermore Academy.

When the mysterious deep space research vessel USCSS Maginot crash-lands on Earth, Wendy and a ragtag group of tactical soldiers make a fateful discovery that puts them face-to-face with the planet's greatest threat.

This James Gunn-created series continues the saga of Peacemaker, a vainglorious superhero/supervillain who believes in peace at any cost — no matter how many people he has to kill. After a miraculous recovery from his duel with Bloodsport, Peacemaker soon discovers that his freedom comes at a price.