Leroy Jethro Gibbs -- I doubt I'd like him in real life, because he's kind of an asshole, but I do like him as a fictional character. And damn but Mark Harmon is pleasant to look at -- as Gibbs, he doesn't smile often, but when he does, I could fall into that smile for days. That one shot in the opening montage in seasons 1-4, where he's on the phone and ducks his head and grins? Hot. Oh, so very hot.
Tony Dinozzo -- again, I like him as a fictional character, but suspect I'd find him to be too much of a jerk for my taste in real life.
Tim McGee -- him, I'd get along with. He's a geek. I like geeks.
Kate Todd -- I'd get along with her, but we wouldn't be close.
Ziva David -- she's scary. I might like her, but very tentatively; mostly I think I'd be intimidated.
Abby Sciuto -- immature, but brilliant, cute, and funny. I'd like her even though I'd find her annoying sometimes.
"Ducky" Mallard -- he's a sweetheart. Like Abby, I'd find him annoying sometimes, but sufficiently interesting the rest of the time to more than make up for it.
Jimmy Palmer -- If I were the same age he is, I'd probably get along with him okay, but we wouldn't be close friends. Given that I'm at least 20 years older than his character, I want to pat him on the head and give him a cookie.
Jenny Shepherd -- way too Type A for me to get along with her on other than a casual basis.
Tobias Fornell -- hard to say. He's a jerk in his professional life, but there are strong indications that he's not all bad.
What I like about the show: ongoing story arcs; people remember what happened previously and apply it. Some loose ends are left hanging. Snark. Intelligence. Good writing and acting that make me care fairly deeply about the characters. Characters who care deeply about each other, even when they don't show it.
What I don't like: stuff gets resolved too easily. Lab work gets done way too fast. The LCD display on the back wall had the same display through the entire fourth season. People get away with shit that would get them fired in real life. People don't always know things they should know (like an entire subplot that should have been in Gibbs' file but apparently wasn't, or if it was, the Director never bothered to read it).