Rick Perry's debate gaffe of forgetting the third federal department he wanted to cut is already becoming part of presidential debate lore. Here are five other famous debate moments that helped shape elections or at least made us chuckle.

Nixon/Kennedy, 1960

The first televised debate is famous not for one specific moment, but for the perception that Nixon looked sickly and sweaty compared to the youthful Kenendy. Many people who listened on radio thought Nixon won, but those who watched gave the victory to Kennedy, who later won the presidency.

Ford/Carter, 1976

Most people say Gerald Ford never really wanted to be President, having it thrown at him following the twin scandals of the Nixon/Agnew administration. If he hadn't, he wouldn't have had thie gaffe where he claimed the Soviet Union didn't have domination in Eastern Europe.

Bush/Dukakis, 1988

Michael Dukakis's cold, unemotional response to a question about the death penalty was poorly received and may have hurt him in the election, which he lost handily.

Quayle/Bentsen, 1988

The same year's vice-Presidential debate also produced a classic moment, with Democrat Lloyd Bentsen coolly putting down Dan Quayle.

McCain/Obama, 2008

It seemed like these two just couldn't stop talking about Joe the Plumber