I would say I like the predetermined ones better, but my favorites are the job systems from V and X-2.

What I love about these two is the meticulous micromanaging I can do. I love micromanaging my characters. Also, your parties have [mostly] the same members throughout the game, so there's no need to ignore any characters.

I hate X and XIII because your characters are designed to grow the exact same way every time you pay the game, but it's disguised in some pseudo-optional manner. It's just irritating to have to manually grow your characters when they really don't have much choice anyway.