You see, I always loved this because it helped show the changes in Tidus' character by the end. He went from being a bit of a whiny jock to selfless hero. I mean he knew he was going to die when they beat Sin. This wasn't a "this is very dangerous and we could be killed" sort of situation. Win or lose, he knew he'd be gone but he fought to stop Sin anyway.
As for what I thought was the weakest moment in the series story-wise, FFVIII comes to mind.
Characters: GF's made us forget we were orphans.
Irvine: I knew you all the entire time but decided to never mention it until now.
Characters: How can we fight Edea now that we know she raised us?
Of all the convoluted piles of crap. I would have preferred them knowing all about their past from the start and realising who Edea was when they first saw her. Would have made a lot more sense and been much less of a slap in my face. I can't stand plot devices this stupid meant to heavy handedly engineer drama. The story could easily have worked without this with a little rewriting and may have had more of a positive impact on me.