The subject title's question and the question asked in the thread are different... *shrugs*
But either way, it's a difficult question to answer, which I think is the reason why many of us have dared to enter this thread!
I haven't watched every cop show out there, so I will omit my answer to that.
No, I don't think it's the best show because there are no such things as best shows for me, just favorite shows. And Monk will stay as a favorite for me!