I don't believe I have ever watched a TV show that displayed character growth the way this one does. You are introduced to the characters in the first couple episodes, but in the next couple you not only learn more about them, they learn more about each other. They begin to grow as a character, change, react differently to situations.
And they shoot, punch, and sometimes even arrest bad guys! You just can't beat it. Sundays at 10pm on TNT.