DeVena:
As the residents of South Park know, he’s quite good in barbecue sauce.
And I forgot to mention my nomination:
Shelley Duval in The Shining .
Just bad on some many different levels.
Another Robin Hood: Prince of Thieves nomination:
“Our fighting days are done.”
Ummm, memorize much there, Kevin?
Snicks
Khaaaaaaaannnnnnn!!!
Blasphemy!!
You’ll certainly get no argument from me on Heist & Prisoner, but I thought she was OK (not great, but not bad) in The Winslow Boy and State and Main, both of which are less complicated, generally warmer characters.
And she only has one line in Pulp Fiction, but Julia Sweeney manages to make hers the worst-delivered in the entire film (yes, even worse than QT’s!).
One more swipe at Andie McDowell: In Green Card, she utters some line about the underadvantaged neighborhood kids that goes “They live with chaos…Despair” or some such thing. It’s not good in the first place, but she really vacuums the intended effect right out of it.
See, this is why I paid $4.95. LOL! I can’t believe you picked this, Nutty Bunny – it was the very first thing I thought of when I saw the topic, but I was embarrassed to post it because it’s such an obscure line from a generally trashy movie that doesn’t get talked about much.
I wonder if David Mamet has issues with women? Because he really does write some excrutiatingly bad lines for 'em.
However, I agree that it’s not just the writing: poor Demi gives a bad reading of a dreadful line. The way she turns on that damn light looking sooooo smug at her staggeringly clever and self-aware comment. BLURG!
(Hmm. I think you’ve given me the courage to post a question that has caused a ragin’ debate between me and my sister for years since seeing the flick. Stay tuned.)
Holy shit! That’s Quentin Tarantino?! I always imagined him as looking…well…more bad-ass.
Yep…that’s him. He was also Mister Brown in Reservoir Dogs, who gave the speech on what Madonna’s “Like A Virgin” was about.
Kinda geeky lookin’, ain’t he?
Actually, his performance in that is worse than his performance in Pulp Fiction…
Potato, potahto, I guess.
To me, you can’t GET worse than his Pulp Fiction delivery.
Empire is far and away the best of the Star Wars movies, but I cringe every time I watch the final confrontation between Luke and Vader and I hear Luke shriek “Noooooooo!” and sob out “That’s impossible!”
I don’t see him as being all that awful in “Pulp Fiction.” Yes, he looks and sounds like a goober. But the character IS a goober. Since he is not really far removed from what the character’s supposed to be like, I don’t see much of a problem. If he had tried to play the Winston Wolf character, then you would have seen some truly bad acting.
That’s because he’s a geek. Why do you think he has such a devout following? 
Tarantino’s acting is awful. One of the best things about Reservoir Dogs is that he played Mr. Brown instead of the character he had originally intended to play: Mr. Pink (thank God Steve Buscemi got cast in that role instead). Mr. Brown thankfully is a fairly small role in the film since he’s dead throughout most of it, having been killed not long after the heist.
Great director, but a terrible actor.
The OP already nailed the worst ever line-delivery. Also, MacDowell’s voice makes me cringe.
Me too, and I think after FW&AF, I finally figured out why. She sounds like she’s desperately trying to cover up a southern accent, and failing miserably.
Ah, the good ones (the horrible Storm line and the horrible Anakin Skywalker sand line) are taken.
And I will listen to no bad mouthing of Groundhog Day. Ramis should have got an Oscar for getting a decent performance out of Andie.
Berry’s performance in Die Another Day was indeed cringe-worthy. She must have been channeling her fine performance as Storm. 
Here’s an interesting one. James Caan (Sonny) in the Godfather is teasing Michael about getting involved in the family business:
“You gotta get up close like this and, bada-bing!, you blow their brains all over your nice Ivy League suit…”
Not bad in isolation, but you should see De Niro’s rendition in his test screening (available on the box set DVD). Whoa! Makes Caan look terrible.
It is clear that the studio bosses wanted a bankable actor in the role, rather than the then-unknown De Niro.
What’s weird is that he must recognise a good line reading when he hears one from one of the actors in his movies, and he writes snappy dialogue… so why is he so incredibly incapable of delivering a good line reading himself?