Mark Harmon's enduring presence on screen has made him a familiar face for decades, particularly for collectors drawn to his television work. While his filmography includes earlier roles in titles such as “Summer School” (1987) or “The Presidio” (1988) that might pop up in budget bins, it's his iconic portrayal of Leroy Jethro Gibbs in *NCIS* that anchors his collectible appeal. This long-running series, spun off from *JAG*, represents a significant chunk of modern television history and boasts extensive home video releases across DVD and Blu-ray, often sought by completists. For physical media enthusiasts, Harmon's *NCIS* seasons are prime targets, often released in comprehensive box sets that are a hallmark of television collecting. Beyond the procedural drama, his Emmy-nominated turn as Secret Service agent Simon Donovan in *The West Wing* (2002) offers a compelling alternate facet of his career for those assembling a prestige TV collection. Even his voice work, like the 2019 animated film *The Wild*, provides a more niche but still valuable entry for collectors aiming for a comprehensive catalog of his diverse contributions to film and television.