The Mask
Diaz's first film role cast her as a torch-singing temptress who distracts the dorky hero Stanley Ipkiss (Jim Carrey) with her hourglass figure while secretly videotaping the bank where he works to assist her thuggish boyfriend in his robbery attempt. She does eventually realize the error of her ways and falls for Stanley (not his green-faced alter ego) but still, that's not the ideal way to begin a long-term relationship.

My Best Friend's Wedding
What better way to humiliate the tone-deaf bride-to-be of the guy you wanted to marry than by making her croon Dusty Springfield's "I Just Don't Know What to Do With Myself" in a crowded karaoke bar? That's the harsh trick that Julia Roberts plays on the sweet, unassuming Cameron here. Her singing voice turns out to be just as bad as advertised and inspires more than a few catcalls. But she sticks with it and wins the crowd -- and even Julia -- over to her side in the end. Wisely though, no one asks for an encore.

Very Bad Things
Peter Berg's directorial debut is filled with nasty people doing nasty things to each other, but Diaz's vicious bride-to-be may be the worst of the lot. Contemptuous of her fiancé, cruel to his buddies and so completely the walking embodiment of a Bridezilla, you can't help but root for a very bad thing to happen to her... which, of course, it does.

There's Something About Mary
You know the scene we're talking about; turning up for their date Mary notices some hair gel hanging off Ted's ear and steals a glob of it to style her own 'do. Of course, that's not really hair gel, but a... uh, spunkier substance. It's a bad moment that will live forever in movie infamy. In fact, when Diaz dies, expect the words "sperm hair" to appear in all her obits. Hell, they may even put it on her tombstone.

Being John Malkovich
Always cast as the glamour girl, Spike Jonze and Charlie Kaufman's utterly unique dark comedy literally showed us Cameron's ugly side. Wearing fizzy hair, no makeup and shapeless shirts, it's the worst she's ever looked onscreen. Good thing her character has such a great personality.

The Sweetest Thing
While recapping a one-night stand in a restaurant, Diaz and her gal-pals (Christina Applegate and Selma Blair) start riffing on how they like to build up a guy's confidence by complimenting his penis size. When some random person starts tickling the keys on a Casio, the trio burst out in an impromptu song. The chorus? "You're too big to fit in here." Trust us, it's as embarrassing to watch as it is to describe.

Charlie's Angels: Full Throttle
It's hard to isolate just one scene from this bloated blockbuster disaster, so let's just label the whole damn thing a 106-minute bad moment. At least the new Charlie's Angels TV show has an illustrative guide to what not to do with this franchise.

In Her Shoes
As Maggie, the screw-up, borderline illiterate sister of Toni Collette's high-maintenance lawyer Rose, Diaz makes a lot of bad decisions. But perhaps her worst is sleeping with sis' boyfriend, which results in her getting kicked of her house and having to move to a Florida retirement community to live with their grandmother. Granted, it ends up working out for the whole family, but having to live in Florida -- and at an old folk's home no less -- is a pretty harsh punishment.

The Holiday
Call it her Risky Business moment. While on holiday in a remote English cottage, L.A. girl Amanda decides to get her groove on by singing and dancing along to The Killers track "Mr. Brightside." Where Tom Cruise came across as charmingly geeky while dancing in his underwear, Diaz's chaotic, ugly moves makes her seem more like a spaz.

What Happens in Vegas
Cameron and co-star Ashton Kutcher both get to have fun being bad, playing a husband and wife who are each trying to force the other to end their hasty, unplanned Vegas wedding. He pees in the sink and takes the toilet seat off, so she invites models over to the apartment to tempt him to stray. It's an hour and a half of bad behavior, capped by the requisite (and totally unbelievable) happy ending.