Right. The last serious third-party presidential candidate was Ross Perot in 1992. In terms of political platform and voter appeal he was slightly more similar to the incumbent Republican candidate George H. W. Bush, which probably enabled the Democrat candidate Bill Clinton to win (although it's impossible to know what would have happened if Perot didn't run).
Some political analysts claim that Perot entered the race not really intending to win but rather as retribution against Bush. In 1979 the Iranian regime imprisoned two of Perot's EDS employees. Perot asked Bush, who was then Director of the CIA, to get them out. Bush refused to act and Perot held a grudge against him ever since.
"In 1979 the Iranian regime imprisoned two of Perot's EDS employees. Perot asked Bush, who was then Director of the CIA, to get them out"
Most interesting part of that story is that once the government failed to help he organized and trained his own operation and successfully extracted his employees.
Some political analysts claim that Perot entered the race not really intending to win but rather as retribution against Bush. In 1979 the Iranian regime imprisoned two of Perot's EDS employees. Perot asked Bush, who was then Director of the CIA, to get them out. Bush refused to act and Perot held a grudge against him ever since.