Gits SAC/2nd gig are taking place at the same time as Movie and Innocence
this is how it works:
Ghost In The Shell <> Stand Alone Complex (Alternate Universe wher the puppet master didn't go active, istead we had the laughing man)
Ghost In The Shell Second Gig
Ghost In The Shell: Innocence <> Solid State Society timeline (Alternate Universe again)
the reason for this is:
Gits movie 1 develops around the time the puppetmaster becomes very active and section 9 investigates
as an alternate happening, SAC develops without puppetmaster involvement, wich leads to a different course of action, SAC is an answer to a question, "What if pupetmaster case didn't exist?" informed by the makers of the original movie, the series continues to develop in 2nd GiG, where Major doesn't have much problems with her work and her morals, everything is different here.
by the time GITS: Innocence works out it's plot, SSS in the SAC universe emerges, the timeline for those is exactly the same, Innocence stil ldevelops around some stuff left behind by Puppetmaster case, altough this time around it's a kidnapping syndicate, and androids going suicidal, it doesn't show directly but it's still under some influence of the puppetmaster case, we meet Major again but not directly, at the exactly same time in the Sac Universe, Major investigates the so called SSS case alone,
the timeline of the movies is exactly like that
GITS <> SAC/2nd gig
GITS2<> SSS
to me, all GITS content is great.