@evol: I wasn't a fan of XII at all, but I really enjoyed XIII. It was actually one of two PS3 games I owned BEFORE I owned the system (the other was SSF4). A lot of people give XIII flack for it being so linear, though I found that kind of refreshing. No "wtf do I go next?" y'know? The battle system was fun as hell too. And I know I'm in the minority, but i enjoyed the characters and.
HOWEVER, XIII-2 (which also seems to have flopped, relatively speaking) I think is an even better game. Gone is the linear gameplay, but it's really really great. It follows the little sister of Lightning, the heroine in the first game.
Oh and they're both stunningly beautiful looking games in HD.
What kills me is I have not finished either (it takes me FOREVER to beat RPG's dood. I play for a week, then put it away for a month or two haha) and I lost all my game saves when I hastily swapped HDD's in my PS3 a few months back.
At any rate, if interested you can get both XIII and XIII-2 really cheap these days. Hell, XIII-2 is on sale for like $15 at Best Buy right now.