if you get the chance,Play X-2. It may clear some things up.

Well, this is a spoiler marked thread. I am not going to mark the spoilers I write,so, your forwarned.

Alright, Tidus was the faiths dream. The faith, by the end,were killed by Tidus and company. Tidus, then, 'died'.He seemed to be an unset by the end of the game,for a moment, before he jumped from the airship and seemingly into the farplane(that would explain Auron,Jetch and Braska at the end). This makes you believe he is in the farplane, gone gone gone forever. This is what X leaves you, BEFORE the credits. If you happen to wait intill after the credits, something else is shown that you have not mentioned.

these things to me no good. My screans set so bright that I can actually read them without highlighting.-.-;;-->[spoilers]after the credits, Tidus is holding his knees in what appears to be water. Perhaps the ocean, because the water isnt as clear as it is in a blitz stadium[/spoilers]. Well, you can then assume that he is alive on the planet ( left un named I believe). Then again, you can assume he is in the farplanes, in the water there. I think there may have been a pyrefly thing around him.

But, like i mentioned, if you play X-2 this would all be cleared up.But, by the end of X, you can simply assume he is alive or dead.