Mt. Bur Omisace was so pretty, as was Paramina Rift.

(SPOILER)The Great Crystal's outside was really nice in Giruvegan, but the inside not so much.

I remember being pretty wowed by the Cerobi Step with it's windmills 'n' all.

Citywise, Archades, even if the areas you could play were disappointingly small.

Nevermind, all of FFXII is damn pretty.

EDIT: Also, as Dreddz said, Eruyt Village is a sight to behold.