i havent read the manga but ive seen the movies and SAC and i would rank them as such:
1, SAC, high quality animation, the cg fits in perfectly, and it has an awesome opening. it has a much lighter feel than the movies and more interesting stories.
2, GITS1, while the plot was lacking i liked the animation style and while it may not match akira it was deifnitely high quality and since i had never heard such a bost i wasnt disappointed with it. I actuaolly watch it every now and then because i find it to be great eye candy.
3, GITS2, the animation i hated, they uglified everytihng, all the character designs were repellent, and the mechanics were just offensive, every single car was from the 1940's which doesnt make any sense, androids looked tubbly and stupid, and wtf was up with that plane? i also say they got way ahead of themselves in the CG to the point where the characters hardly went along with anything, they would look like flat paper cutouts in a 3D environment. It was painful to watch, tihnk of it as a riced out lamborghini, high price, high quality, but ugly as sin for no damn reason. The story was alot better than the first but animation put me off so much that i really cudnt enjoy it