4. Michael Madsen
Reservoir Dogs is one of the most iconic films of the last twenty five years, having introduced Quentin Tarantino to the world in style. Though it was his subsequent film, Pulp Fiction, that made people really take note, there are a number of film fans (myself included) who would consider Reservoir Dogs the superior film. One of the film's most iconic sequences comes when the psychopathic Mr. Blonde, played by Michael Madsen, tortures a captured police officer and cuts off his ear whilst dancing to 'Stuck In The Middle With You' Madsen was Tarantino's first choice for the role of Vincent Vega in Pulp Fiction as well, but committed to Kevin Costner's Western Wyatt Earp instead. His career has since gone rapidly downhill in recent years, and despite showing up in Kill Bill, Sin City and Die Another Day, he really scraped the bottom of the barrel in 2012 by appearing in Celebrity Big Brother. This came just two years after he appeared in 24 playing Jim Ricker, an old ally of Jack Bauer's from the Gulf War that provides him with assistance when he becomes a target of the US government.
3. Zachary Quinto
Most of the characters played by the people on this list were minor ones that only showed up for a few episodes. Zachary Quinto managed to rack up twenty three as CTU employee Adam Kaufman during the third season, without ever being particularly prevalent in any of the season's many storylines (relegated mostly to assisting Kim Bauer throughout the course of the day) or notable by his absence or lack of mention in any future season, though he did appear in 24: The Game. The role came three years before Quinto landed the role of Sylar, the breakout character of Heroes, which was initially a huge hit before rapidly going downhill in its later seasons. Like 24, it is being brought back in limited-series form, which should see the actor reprise the role that led to him being offered the role of Spock in J.J. Abrams Star Trek reboot.