and the labyrinth
The Sound of Music
Every time Apocalypse Now is on I flip to it and think “I’ll just watch a few minutes of it.” Flash to an hour or so later and I’m still watching it. Epix has it on quite often, so I fall into this trap all the time.
Some day this war’s gonna end…
Contact
Porky’s
All of the Marx Brothers movies
For some reason lately I can’t get enough of Knight and Day. I’ve spent entire weekends watching it on a loop.
Also:
Baby Boom
Working Girl
Any of the Bourne flicks
The Usual Suspects
All of the Hugh Grant movies (Yes, even Mickey Blue Eyes)
And that one with Mark Ruffalo where Reece Witherspoon is a ghost.
T2
The Princess Bride
the Wizard of Oz
The Big Lebowski
The Little Princess (Shirley Temple version)
The first 10 minutes of Super Troopers. Not the entire movie, but that opening scene is one of the funniest of all time. I never tire of it. 
Ooh yeah, and The Princess Bride
National Treasure
Drive Me Crazy
X-Files: Fight The Future
and, like Infovore, any of the Harry Potter movies I stumble across on ABC Family.
With the exception of Harry Potter and the Deathly Hallows part one, which I’ve forgone in favor of whatever special set of parts one and two sure to be released this Christmas, I own every one of the movies I listed on DVD too, yet if I stumble across them…
I think I really only have two -
Dazed and Confused
American Graffiti
Any time, day or night, I’m flipping through the channels and one of those is on, I’m stuck to the tv.
Oh–Add Victor/Victoria to my list, not that it’s on much these days.
Sweet Smell of Success - I watched this, on TCM, at least three times in the last couple of months.
The Long, Long Trailer, with Lucy and Desi. I think this movie has such utterly hilarious moments, and that trip over the mountains!!!
Roll, Bounce - starring “Bow Wow” - a disco rollerskating competition. I’m sorry, I LOVE the music, I’m in awe of rollerskating dancing, and it’s a good, clean, family friendly all around cute movie. (and you can spot Paris Hilton sticking her face in the camera in a couple of scenes).
Most of the Doris Day oeuvre. I hate her, but I love her. With Six You Get Eggroll and Love Me Or Leave Me are my favorites.
White Heat, with James Cagney.
Houdini, with Tony Curtis and Janet Leigh.
Yours, Mine, and Ours, with Lucille Ball and Henry Fonda. Where each of them has a dozen kids but they get married anyway.
DuBarry Was A Lady - because there is the corniest, cutest retro segment of ‘calendar girls’ , each one dressed up appropriate to the month. (February - Valentine’s Day, October, Halloween). Like an old-fashioned pinup girl calendar.
Of course, Goldfinger. My favorite Bond movie. So many classic moments.
Casablanca, Citizen Kane, Maltese Falcon, Godfather I and II, The Man Who Shot Liberty Valance. I don’t think those have been mentioned yet. Lot of great picks in the thread.
French Kiss
Von Ryan’s Express, for some reason. I like it but I would hardly list it as a contender for “greatest movie ever”. But it is well-paced, scenic Italian countryside, Sergio Fantoni looks cool as the
the Italian with an eye patch, Trevor Howard looks comically stupid when he has to dress up as a German soldier.
Roadhouse. Any of the Rocky movies. Silverado. The Untouchables.
Steel Magnolias
I suppose that’s complete confirmation that I am fundamentally female.
An Affair to Remember - a real tear jerker. I can also see the US Navy ship (flagship of the US 6th Fleet) that I lived on for nearly two years, homeported in the harbor of Villefranche sur-Mer on the Riviera. As Cary & Deborah are riding up to his grandmother’s villa, you can see the ship between some buildings.
Ronin, which was also filmed partially in VsM and nearby Nice, et al.
Tremors
Jaws
Forrest Gump
That Thing You Do
Videodrome
Repo Man
Female Trouble
Lady In A Cage
Miracle Mile
Times Square
Bride Of Frankenstein
12 Monkeys
Caveman
Island Of Lost Souls
Spun
Whatever Happened to Baby Jane?
Freaks