I liked Ghost In The Shell well enough, but it wasn't a fantastic film. Maybe it was me at the time, but a naked cyborg floating on the sea philosophizing about the nature of humanity wasn't my cup of tea. There was a LOT of philosophizing in GITS, and while I accept and love that commonality of Mamoru Oshii's films, there was just too much here for my tastes.
Much better are his Patlabor 1 and 2 films, and especially Ghost in the Shell 2: Innocence. Not only was the animation better than anything that had come before it, but the philosophical questions bandied about in 1 that came off as ponderous and academic actually took hold in 2. It actually made me stop and think about the central question of the film: How do we know we're even here? What if we're hooked up to a computer in a lab somewhere, running an elaborate simulation?