So, having played through disc 2, I've now hit the point where I've been advised to stop and make up my own ending, because what little plot coherency the game has totally falls apart at that point. So...

Rinoa finally admits that she's only been hounding Squall to hide her deep and undying love for Selphie. They buy and re-open Raine's bar and live in lesbian bliss. Quistis takes over the orphanage, because she likes being Everybody's Mom, and earns a reputation for being kind but firm. Irvine becomes a stripper in Deling City (look, he's got man-whore written all over him, okay?). After becoming a world-class fighting champion, Zell decides that it isn't the life for him, and uses his prize money to buy a boat and become a world-class fisherman instead. Squall buys a big house in the middle of nowhere with lots of cats, and enjoys not having people yelling at him to get things done. He visits Quistis and sometimes teaches special classes at Balamb Garden (which Cid and Edea fix after it's unfortunate collision with Galbadia Garden) when life in the middle of nowhere gets a little too boring. And everyone lives happily ever after, or at least tries to, the end.

EDIT:
Jo: What about Seifer?
Me: I...don't know. I tend not to pay very much attention to him. He hangs around the Garden worshipping the ground Edea walks on some more?
Me: And possibly has hot gay sex with Squall when they can get all the cats out of the bedroom.