Oh man, this is a trip, especially since some of them only make a single appearance. I really loved Magic Knight/Sorcerer from FFV, for example, one of my favorite classes to make Galuf, rocking his turban, wreaking magical havoc with his sword.

True job class, i just might have to go with Monk, as they seem to be one of the most underrated classic job classes (see FFI guide on this site). Not as easy to master as Warriors in FFI, but i feel that in that game, and nearly all its successors, once you really put effort into them they become powerhouses. I like how Tifa's limit break worked in FFVII, and how eventually you can just master the timing of the slots as if it were second nature.

I really like what they did with Zell. Making limit breaks more interactive in VIII was one of my favorite aspects of the game, I always loved using Zell's.

As far as the weak link, I might say in FFXII because there's just nothing enticing me to use it. I really wish they structured the license board better, but the international/european version was a little overboard. That's part of why the character development system in XII is my favorite and least favorite. It's just so great when you're actually buildilng your characters, but damn, when I get really into the License board, especially the top half and technicks specifically, I just can't help but thinking how poorly it was thought out.