The writing and the characters/acting, the two most important aspects of any show, are both excellent beyond description. I love all the characters, and they have a great balance between them!
Gibbs is my hero. The man's tough as nails, in fact he drinks his alcohol out of a glass jar he keeps his nails in for crying out loud! More importantly he follows his own sense of justice and will not tolerate or even consider abandoning his rules in favour of some law or regulation. He is dogged, he's old school, he's fiercely loyal to anyone he deems worthy and just as fiercely condemning of anyone who violates his sense of morality.
It's great that we've finally gotten to learn some of his past since the finale of season 3.
Anywho I'm fastly addicted now, and I've asked for as many of the DVDs for christmas as my family is willing to buy me