I used to like Vaan when I first played XII, saying he was better than Tidus. That was a load of crap. He really has little reason to be in that game, his voice-actor is noticeably worse than everyone else and overall I just wish Larsa was a real party member instead.

My second time through, I was more lenient on Lightning. Only in FFXIII, though. Can't stand her in the sequels.