Depends. A Title Like Final Fantasy Tactics where outside of some special characters there are no personalities? Full Customization.

A game like FF IV or IX? Give me the predetermined Rolls. In regards to VI I feel you had to much ability to turn any character into anything you wanted, though that takes a bit more knowledge on the game then you are likely to have if you are new to the title (Though a lot of previous RPG experience may change that), and VII and VIII just got crazy with it.

Xenosaga III still has one of my favorite set ups for giving you some customization for a character while keeping it sensible to the character itself. I would love to see that expanded upon.