Jimmy Hoffa

James Riddle Hoffa was the powerful and controversial leader of the Teamsters Union from 1957 to 1971. Often alleged to have ties to organized crime, Hoffa was finally convicted of fraud and jury tampering in 1964 and served four years in prison before his sentence was commuted by President Nixon. In 1975, while trying to regain power in the union, Hoffa disappeared from a restaurant parking lot in Bloomfield Hills, Michigan. He was widely assumed to have been killed by the Mafia. His body was never found, and in 1982 he was declared legally dead. In September of 2001, news reports claimed that DNA tests by the FBI had tied Hoffa to a car driven by his associate Charles O'Brien the day Hoffa disappeared -- suggesting that charges might still be brought in the case.

Extra credit: Hoffa's son, James, became president of the Teamsters in the 1990s... Both Robert Blake and Jack Nicholson have portrayed Hoffa on the screen.