I don't consider the Compilation a spin-off because it picks up the same story as VII. That's like saying the Matrix Reloaded was a spin-off. Just because you don't like the direction they went with a story in a sequel, doesn't mean you can discount it from canon (unless it gets retconned). Final Fantasy Tactics and Vagrant Story both come from the same world as Final Fantasy XII but do not directly continue the story. The same is true for XIII, XV and Type-0. Those that I consider offshoots are titles like Tactics Advance, Crystal Chronicles, Theatrhythm, the Chocobo series, Dissidia, and the games that are listed on the Final Fantasy Wiki as spin-offs. Also Kingdom Hearts.