A 19-season-long medical drama, Grey's Anatomy has become notorious for being one of the best procedural shows. Keeping a devoted audience for four seasons is difficult enough. Still, Grey's Anatomy maintains its audience for 19, going on 20 seasons, not thanks to its plethora of medical cases but to its large cast of characters.
Source:https://www.cbr.com/greys-anatomy-best-characters-ranked/