I've already talked about Tony DiNozzo, one of the greatest characters on my favorite tv show, but Tony isn't my favorite. My favorite, all hands down, is Ziva David. She's a former Mossad officer who joined NCIS after her brother (who was awesome in season one) died. She's tough as nails and completely dauntless. Nothing scares her, but she's still fun-loving with a great sense of humor. And besides, she once killed a man with a credit card!
What I really love is that she never whines. Her predecessor, Kate, whined and griped a lot, but Ziva just takes whatever comes and does whatever she needs to do, no questions asked. She demonstrated that when she shot her own brother to save Gibbs's life. You go, Ziva!