NCIS has been on the air for an impressive 17 seasons and is gearing up for Season 18. Since its very first episode in 2003, Gibbs (Mark Harmon) has been leading highly skilled investigators to solve some of the world's toughest crimes.Though big characters have come and go, including DiNozzo (Michael Weatherly), Ziva David (Cote de Pablo), and Quinn (Jennifer Espisito), the main cast has mostly remained the same for ages, with heroes including Sloane (Maria Bello), Ducky (David McCallum) and, of course, that irresistible Torres (Wilmer Valderamma) drawing in millions of viewers every week to see how they save the day.
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