GITS is my favorite scifi anime, here is the order
1st movie (1995) : "just to see" (you probably saw this one)
GITS Stand Alone Complex - first season (26eps)
GITS Innocence (2nd movie, independant from the serie, more like sequel of the 1st)
GITS SAC - 2nd Gig
GITS SAC Solid State Society (3rd movie, epilogue of the SERIE)
manga is 2x2 vol, and is really, really poor ... good ideas but the animation team writers were very, very good. some episodes are individual (stand alone), some others are part of the main serie (complex), some are both ( O_o

)
they developed the manga far far better, really great, by design, animation quality, musics (yoko kanno !), and the way this hi-tech level (cyber brains, cyber meetings and breaking news, the future you would like to live in

) AND political, post-3rd WW background, AND adorable-kawai-cute tachikomas, kind of living artificial beings ...
really, really a must see for a sci-fi fan, i promise. this is just ... GREAT, 52x20 + 3x100 min of astonishement and drooling

Experience is the name everyone gives to their mistakes. (Oscar Wilde)
Corporations have no soul to save, and they have no body to incarcerate. (Baron Thurlow)