NCIS has had numerous cast exits throughout its 20 seasons. While some departures were due to story direction, others were the result of cast members choosing to leave. However, the show has successfully handled these changes and introduced new characters seamlessly. Despite this, there are certain characters fans would love to see return. Mark Harmon's Gibbs, Pauley Perrette's Abby, Cote de Pablo's Ziva, and Michael Weatherly's Tony are at the top of the list. Fans hope these beloved characters will make a comeback, even if it's just for a guest appearance.