Jaws, Duel, Schindler's List, the first Indiana Jones, all very close together.
Jaws was the first movie I was allowed to go see on my own, so that'll always be near the top for me, I can still recall the audience standing up and cheering madly when the shark blew up. Duel is one I remember from loving on TV, brings back great memories of watching it with my mom and sisters, while eating popcorn and artichokes. Schindler's List is an obvious labour of love for SS, very moving film, one I've never tired of viewing. I liked how the first IJ film touched on historical fact, which elevated a great action film to an all time classic for me.
Haven't seen any SS films in the theater since Schindler's List though, I've caught bits of The Terminal and Jurassic Park on TV, interesting in places, but not enough to make me wanna go out of my way to see the rest.