4. Agent Tom Baker
Daniel Dae Kim might be most recognisable to many for his work as Jin on Lost, but before that he appeared in 11 episodes of 24 as Agent Baker, a memorable Asian agent who often assisted Jack and others, proving himself a sure badass in the field. Baker quickly earned a fan following as well, though never appeared in the show again once he scored a gig on Lost. Now that his commitments there are over, how awesome would it be to see Agent Baker make another appearance to help Jack? For those who suggest that too much time has passed since Baker's appearance, remember that 24 has brought obscure characters back before; Dr. Sunny Macer, who appeared once in season three as a virus analyst, appeared again in season seven for another one-off episode, and Milo Pressman (Eric Balfour), who appeared in eight episodes of season one, and then returned for a season-long run in season six.