Blade Runner
Star Wars / Empire Strikes Back
Lord of the Rings Trilogy
Pretty much anything by Danny Elfman
The Fifth Element
Dredd / Tron / Dune
Those are all in my "always available" playlist for my phone. Blade Runner, however, is the one I listen to the most by a wide margin.
Edit: Man, I'm scrolling through my library and so many others I love. Mancini, Herrmann, Clockwork Orange, Legend (both Tangerine Dream and Goldsmith), The 13th Warrior, Harry Potter...
Don't make me choose!! (But if I have to choose, it's probably Blade Runner)