Why Are Falls Funny? Most Popular of YouTube Videos [Video]

Why do we laugh when people fall? I guess it's a nervous reaction because we certainly don't get off on people being injured. Well, the most popular videos on YouTube include falls and other mishaps.

Warning: some are pretty rough. Here's the best 100 videos that have marked the YouTube era. It begins with a shoe being thrown at Pres. George Bush and rifles through hundreds of falls and accidents.