I'm a big fan of the show. In thinking of why this show stands out to me, I come to the conclusion that it is a fantasy for thinking adults, much like the fantasy that Disney is to small children. Well, think about it. Although the occasional criminal gets off by a technicality to make it look realistic, the fantasy aspect is still clear. The fantasy is in the depiction of the police and the prosecutors as unrelenting in the pursuit of justice.
Many shows even portray a struggle between different jurisdictions for the right to prosecute.
I, for one, enjoy the fantasy. I like thinking that they are always there for me. It is how our law enforcement officials are supposed to behave in the ideal. They have taken an oath of office to do the right thing. They are the police and prosecutors rolled into one for the commodities industry.