Alex Trebek, Vigilante

He's not just the host of "Jeopardy," he's also a vigilante. Alex Trebek appeared on crutches on July 27, 2011 while hosting the National Geographic World Championship. The reason: He was chasing a burglar at his hotel in San Francisco, Calif. in the middle of the night when his Achilles tendon snapped. Trebek said when he fell, he also injured his other leg. Trebek, 71, assured the audience that he was OK.

Wow, he's 71? Yes. Turns out his birthday was just the other day on 7/22.