The Sentinel has a very unique concept that makes the show special. The series is about a cop who has five enhanced senses and the problems and advantages that come with them.
The one thing that puts this show on top of my favorites is the great character interaction and the character development. From the first episode on we witness a very special friendship develop, and see all its ups and downs during all four seasons. Not only are the main-characters well written and a joy to watch, but the supporting cast is great too. It's a shame that UPN cancelled the show after 65 episodes and that the finale left a lot in the open.