Favorite Villain
Hmmmm....I'd have to say Ari. He was a great bad guy and a great story arc. I loved how he would go toe to toe with Gibbs and Gibbs' team, but Gibbs wouldn't need to to bring in "help" like this season. He also had a really cool and somewhat believable psychological reason for being a killer, which I loved. His obsession with Gibbs was also believable for a sort of serial killer plot line, so it was even better. And I thought that the two Kill Ari episodes were really well executed. All in all he was a really well-written villain that was perfect for Gibbs!
He was also really hot ;)