Star Wars... i used to watch it pretty much weekly after recording it off the telly in the early 80s. There was bugger all else on.
An American Werewolf in London... faultless fun from start to finish
2001... just to try to work out WTF goes on at the end.
Brazil... ditto. I think after the 8th viewing i finally sussed that he wasn't saved in the nick of time and actually had a lobotomy.
Amelie... it's pretty much a perfect film.
Contact... possibly my favourite sci-fi of the 90s
Fargo... i'll never tire of the characters.
Oh Brother, Where Art Thou... another perfect film.
Once Upon a Time in the West... it's a classic
This is Spinal Tap... after Sabbath, they're the world's best metal band, even if they're not really real.
Christopher Guest directed films, Waiting for Guffman, Best in Show, A Mighty Wind, For Your Consideration... are all joyous to watch.
...and many many more... I only buy DVDs that are worthy of numerous views.