I got XIII for $12 including shipping, so I'm giving it a shot.
I honestly got bored within the first hour. They're not kidding this stuff is linear. Beautiful, but so far it's been nothing but ramps... And I had to sit and dig in menus to "catch up" on the back story because the cut scenes weren't enough to clear things up...
There's just a few simple rules you have to remember:
1. Hope is short for hopeless. He might be the best caster, but he usually spends most tough battles being dead. Not a good feature in a healer.
2. Sahz is the man mid game, use him often, but he peters out towards end game.
3. Lightning is the best all-rounder and the quickest attacker. Throw her in if you don't know who else to add. She's the main character for a reason.
4. Sabotage raises the chain meter and it doesn't degrade as fast as ravaging. It can be useful to remember that sometimes.