Star Wars Episode 4: A New Hope.
Because the whole film takes place in space, on other planets other than earth. It has good guys, bad guys, hot guys (see Han Solo.) It also had great British actors, Alec Guinness for one.
It's exciting, romantic, funny, sad, happy. Has all the emotions you could ask for. Plus all the characters are memorable.
Plus the soundtrack kicks ass. Period. Nuff said.