@andrew, lurve for NCIS!
TBH, I feel NCIS is superior to other shows because of the characters (and Michael Weatherly), not necessarily because it’s a procedural. Unlike the various CSIs, there is a lot of character development (and story development). The stories, although similar, aren’t the same time after time after time.
Sort-of on topic: I feel strongly that one of the reasons why Joss Whedon’s shows do as well as they do (I’m talking more staying power and cult-status than necessarily ratings) is because they aren’t procedurals, and rarely (if ever) deal with the police/feds/lawyers/normal jobs/etc.
(His shows are sort-of professional shows: the life of a slayer and her friends, the life of LA’s champions, the life of some western pirates, the life of a “doll” who has her mind wiped but goes on missions as her job, etc.)
Also, Joss is great about throwing together several genres and making it work, whereas, most other tv shows wouldn’t know genre variety if it danced in front of them wearing a tea cosy.
Finally, there aren’t very many good writers on tv, but there are a lot of mediocre ones. Like others have said—it’s “easy” to write a medical/procedural/judicial drama, which is the path many of said mediocre writers take.
I’m incredibly long-winded, I know. Feel free to ignore me. :D