18. Daniel Dae Kim
Lost was nothing short of a phenomenon during its six years on the air. Focusing a group of plane crash survivors on a remote island, its mythology and array of mysteries and complicated character relationships generated a cult following that remains strong even four years after its finale. The show featured an ensemble cast of main and important recurring characters, many of whom have also appeared on 24. Perhaps the most notable of these is Daniel Dae Kim (who played Jin on lost and currently plays Chin Ho Kelly on the Hawaii Five-0 remake), who played a CTU agent that assists Jack and shares his name with the Fourth Doctor Tom Baker during the show's second and third seasons. Other alumni from the show to have appeared on 24 include Alan Dale (Charles Widmore), who was David Palmer's Vice President, Jim Prescott, Henry Ian Cusick (Desmond Hume), who played German agent Theo Stoller in two episodes of 24's fifth season, Doug Hutchison, who played Dharma Initiative leader Horace Goodspeed on Lost and the assassin Davros on 24, John Terry, who played Christian Shepherd on Lost and Bob Warner on 24, and Francois Chau, who played Dr. Pierre Chang on Lost and shared scenes with Jack Bauer as Chinese consul Koo Yin.
17. Leighton Meester
Teenagers are highly important to television executives, and are the targets of a sometimes disproportionate amount of programming in comparison to other demographics. In fact, the CW, America's fifth largest network after the traditional 'big three' (ABC, NBC and CBS) and Fox, is geared almost exclusively towards them. One of the network's biggest scripted successes since it was formed in 2005 after a merger between UPN and The WB has been Gossip Girl, which ran for six seasons between 2007 and 2012 and featured Blake Lively and Leighton Meester in the respective lead roles of Serena Van Der Woodsen and Blair Waldorf. Two years prior to the series' premiere, Meester featured in five episodes of 24's fourth season as Debbie Pendleton, the girlfriend of Arab-American Behrooz Araz, who is forced to break up with her at the urging of his parents, who are supporters of Habib Marwan's terrorist plot. Wishing to work out why she has been unceremoniously dumped, she travels to his house, becoming a sacrificial lamb of sorts when she is murdered by his mother (Oscar nominee Shohreh Agdeshloo) after he refuses to do the deed himself.