I'd go for chronological order. That's the order I watched them for the first time and it worked out well for me, IMHO.

That means first watch the movie Ghost in the Shell which is also called Ghost in the Shell 2.0 which is a re-release of the movie with some added CGI to the intro. That being the only major difference.

Then watch the 2nd film. Not to be confused with the "2.0" re-release of the original film. The name of that is Ghost in the Shell 2: Innocence.

Next, it's on to the TV show. Now, some of the content from the first two seasons was turned into two movies. So, I suggest watching the TV shows in their entirety. Then watching those two movies. So the order there would go like this.

First watch Ghost In The Shell: Stand Alone Complex. That would be season one. Season two is called '2nd Gig'. Then you can watch the movies, The Laughing Man and Individual Eleven.

After you've finished watching all that. The next movie for you to watch is Solid State Society. This film takes place shortly after the last episode of 2nd gig. Or, for you after you've just finished individual eleven.

Lastly you can move on to the new Arise series. Which is a prequel to everything you just watched. It goes back to when everyone was younger and takes a look at those days.