for me it was either the time machine 2002, or rollerball r rated 2002 (not even rebecca romaijn stamos naked could save that train wreck)

Non-MST3K Manos, Hands of Fate.

I nominate "Mixed Nuts" - screenplay written and directed by Nora Ephron.

And I utterly loathe "Ransom" by Opie Cunningham - but that's a personal issue and not really a reflection on the awfulness of the finished film.

It's tough for me to think of bad movies I've seen because I tend to block them out of my mind to the point that I can't remember (fortunately). But out of the movies I can remember right now, I'd probably say Vertical Limit.

Rawhead Rex

Unseeable by Shyamalan
Thin Red Line by whoever directed it.

Rebecca Romaijn Stamos was naked in that? I'll have to check that movie out.

My list of the crappiest of the crappy:
Batman & Robin
Batman Forever
Con Air
Face Off
Jaws 4

Movie Movie

The Island of Dr. Moreau

I got exactly 3 chances to see this:

1) on a coach bus from LI to Boston
2) Rental
3) Friends house

and on all three occasions I fell asleep about 20 mins into it without fail. Either the thing is full of subliminal messages that make me sleepy or its just plain boring.

Gymkata

I've seen tons of crappy movies on cable, but that I actually paid for to see in a theater, I'd say either Wild Wild West or Batman & Robin. Yet, the completist in me forces me to own B&R so I can have the complete series. Doubtful I'd ever watch it again unless I wanted to do a homemade MST3K type thing.

Lifted from a previous post of mine with the authors permission
Top 20 Movies in no particular order
Dinosaur (2000)
Gattaca (1997)
Hannibal (2001)
Legend of Bagger Vance (2000)
Avengers, The (1998)
Batman & Robin (1997)
Cast Away (2000)
Ladies Man, The (2000)
Red Planet (2000)
13th Warrior, The (1999)
Art of War, The (2000)
Last Action Hero (1993)
Mystery Men (1999)
Ransom (1996)
Spice World (1997)
Street Fighter (1994)
Lost World: Jurassic Park, The (1997)
Valentine (2001)
You've Got Mail (1998)
Magnolia (1999)

I'll double that Hannibal vote.

How about that golfing film with Randy Quaid that came out in the 80's? That really blew.

How I wish I could say that the worst movies I have seen were already listed here, but with the exception of "Manos, Hands of Fate" most of these were bad to mediocre, but far from the worst. The worst movies I have seen would have to include:

Manos, Hands of Fate
CHUD II: Bud the Chud
Police Academy: Mission to Moscow
Leonard Part 6
and all of the Silent Night, Deadly Night series

These were truly awful movies, I know of no one that found any of these entertaining in any sense beyond that which makes one look at a car crash...

Ishtar

I agree, assuming your referring to the Val Kilmer, Marlon Brando version.

I'll also throw in Freddy Got Fingered. A movie so bad I can't even put it in words.

I will second Rollerball
A couple of movies i viewed with my wife Sleepless in Seattle, You've Got Mail, Joe Versus the Volcano.

Rumble in Hong Kong (also known as Police Woman) (1974)

from recently, I'd have to say Crazy Beautiful

Hart's War
Unbreakable
Freddy Got Fingered

The Last House on the Left

I can't believe nobody's ever thought of this as a thread topic before!!!

I'm torn between Citizen Kane and The Godfather, I can never quite make up my mind which is the worst movie.

The Blair Witch Project

Of course this is out of the movies that I saw that were in "major" release. B movies don't count.

BTW: It is funney that some of the above movies are in my top 50 if not higher. I guess to each their own.

Ecks Vs. Sever (omg...this has to be the first movie I really wanted to walk out on)

Mr. Deeds (new version...I loathe Sandler)

Big Fat Liar (I was unfortunately forced to see this)

The Tuxedo (Boring, unfunny, grossly paced movie)

Mission to Mars (Bored to death)

I know I can think of a LOT more but I am too tired to think, maybe later.

Offhand: A Scream in the Streets

or: Behind Locked Doors

Both completely worthless.