What made this show such a hit was the main fact it was about a detective who has OCD and has alot of bizarre quirks. I mean, who didn't love watching Monk getting all bent out of shape at times due to his phobias and speaking his lingo. It was just a riot!
The supporting characters were top notch as well. From Sharona Fleming, Captain Stottlemeyer, Randy Disher, Natalie Teager and Trudy Monk.
The show sadly never was the same after Sharona was replaced by Natalie. While Natalie did a decent job, she just didn't have that spunk and attitude as Monk's first assistant that you just couldn't help but love.
Stottlemeyer to me is what you would think of when trying to describe a cop. Tough and all business. Randy Disher on the other hand is what you call a suck up, trying to impress the Captain by any means necessary. His crazy theories for how a murder was committed was just hilarious.
Anyway, as for the stories, I for one thought they were very well written. The writers were very creative on how to show the "who done it" theory. Just about every episode I watched the first time had enough intrigue and mystery to keep you interested and try to figure it out.
All in all, this show is definitely worth watching if you need a good laugh and mystery.