This is the end...

[Alucard von Elru]

FFX's ending definitely gets my vote for the best of the series. That's not entirely giving it enough credit, however, as I've found the endings to nearly all other FFs to be at best either dry or disappointing. To give it the credit it deserves, I should say that FFX's ending stands as one of the greatest to ever hit an RPG, period.

EDIT: Excellent, excellent article on Tidus, by the way. I've always absolutely loved his character. For me, he was the first FF character I really thought of as being human and fully developed. FFX's story in general is a phenomenally-written piece, and Tidus' entire arc of development from start to finish is more than indicative of that.