I understand what you mean about that "first time" experience missing during subsequent play-throughs. It's much different when you know what's going to happen.

But I enjoy second playthroughs just as much, only in a different way. The first time through offers a fresh story of which you know nothing about, and it's so enjoyable because the story is unfolding before you. However, I enjoy second (and third, and fourth...) playthroughs for the same reason. What I mean is, because I know how to do everything already, I can play without the stress of not knowing which way to take in a dungeon, and additionally, my characters are always better developed after my first game. I spend more time on them, and it's more fun in that regard.

So far, I've played through FF7 five times, FF8 four times, FF9 three times, and FF10 twice. I've only played through FFs 1, 2, 4, 6, and 10-2 once each, but I can see myself playing through 4 and 6 again.