after the good ending a+b u get a bonus ending for the perfect enging, tidus and yuna stood in zankerkand ruins
Perfect Ending
--------------
* See this after the Good Ending after you see the credits
[ Tidus and Yuna are standing in the deserted Zanarkand Ruins ]
Tidus: I got a theory.
Tidus: I think the fayth gathered up my thoughts and put 'em
together to bring me back.
Tidus: Maybe. Something like that.
Tidus: Or maybe.. I'm still a dream.
Yuna: Wait! so you'll dissapear?
Tidus: Cherish me, Yuna. And I'll cherish you.
Tidus: All right? We gotta stay together. That's what we have to do.
[ Yuna runs up and holds Tidus from behind ]
Yuna: Is that what the Fayth told you?
Tidus: Nah. But I like it.
[ Yuna and Tidus laugh then Yuna pushes Tidus into the water ]
Tidus: That's not cherishing!
Yuna: You didn't disappear.
[ Yuna smiles ]