My top 10:
10. Selphie-I'm usually not the hugest fan of FF's upbeat girls, but Selphie is an exception because she's so much odder/crazier than the others and has a dark sense of humor that is at odds with her bright vibe.
9. Red XIII-I found his quite, reserved personality to be extremely endearing. And that scene when he found out that his his father was not a coward was touching and brilliant.
8. Quina-I don't care what anybody says. This weird thing is awesome. It's refreshing to have a character with such a simple outlook on life.
7. Wakka-Wakka has an endearing big brotherly charm and an interesting accent, but what makes him one of my favorites is his sophisticated character development. His bitterness toward the Al Bhed was fueled by the fact that his brother used Machina to fight Sin rather than the homemade sword that Wakka made for him. This, IMO, is a subtle and interesting rationale for his bigotry (not saying that justifies it; it's just a really good slice of characterization).
6. Terra-I'm a sucker for underdog characters who manage to stay pure of heart even when the world seems to be against them.
5. Balthier-Balthier probably has the most swag out out any FF character. He is incredibly charismatic and I loved just listening to him talk. All of the best lines in FF12 belonged to him.
4. Laguna-It was too bad that Laguna was the lead of a secondary plot because the aura he gave off of just being a really good person was such a refreshing contrast to Squall's terrible attitude. His convincing klutziness around women just added to his charm.
3. Zidane-With his upbeat personality and his endearing pursuit of women, Zidane was so preferable to other famous FF leads like Cloud, Squall, and Tidus. I especially liked the way he acted as a kind of big brother figure to Vivi.
2. Doctor Cid-Some of you might be surprised to see this guy on my list, but I thought he was easily the most interesting and overall best villain in the series. He had the same charismatic way of speaking as his son, but had a certain intensity that kept me glued to the screen whenever he was in a scene.
1. Vivi-The ultimate pure of heart underdog character. Not only is Vivi insanely cute, but his character development and quest for identity was both impressive and emotionally engaging. I don't think I've ever felt for a video game character more than I did with Vivi.