Persis Khambatta beat Demi by over ten years in the first Star Trek movie.
Vincent D’Onofrio put on 70 pounds to play Private Pyle in Full Metal Jacket, then immediately lost it and a few more to play the super-buff Dawson (a/k/a Thor) in Adventures in Babysitting.
From IMDB.
What about unsuccessful attempts to get roles? I’m remembering when Sean Young showed up on the set of a Batman movie dressed as Catwoman to try and get the role.
Doesn’t count if you’re not an internationally renowned sex symbol, sorry. My post, my rules ! 
Whoa, that was the same guy? I would never, never have guessed that.
As for the other actresses who had sex in a mainstream movie being less than famous, let’s be honest, here: Who here had ever heard of Chloe Sevigny before The Brown Bunny?
She was nominated for an academy award in 1999 ;). Brown Bunny wasn’t until 2003. She mostly acted in more art house-type films, but could probably have been considered a moderately well known young character actor before acquiring her fellatio fame.
It was actually far worse than that: Landis was also violating child labor laws when the scene was shot. Morrow was doing the scene with two children, ages 6 and 7, in the middle of the night, and it is not permitted for kids to work that late. So the director paid them under the table and hid them from safety officers. Then the helicopter crashed, decapitating Morrow and one of the children and impaling the other. All 3 were killed. I read an article on it that was utterly nauseating.
As for the thread topic, Michael Weatherly (Tony DiNozzo on NCIS) was disowned by his rich parents for becoming an actor. Kind of ironic that his character plays a guy disowned by his parents for pursuing an unapproved career. Though I guess Weatherly has kind of stuck it to his parents since then, as I can’t imagine he’s wanting for much financially at this point.
He may have “bulked up” for Dark Knight, but I really did notice how they seemed to put some effort into avoiding showing Bale shirtless in DK, so I suspect that he fattened up but didn’t have time to get buff and muscular. The one time he changed his shirt on camera, he did it with his back to the camera, and they filmed it so you only saw the fresh, clean shirt fabric. If he was buff, you’d think they’d make a point of showing off his physique when they had the chance to flash some beefcake.
I do know from an interview that prior to Batman Begins, he said he restored his weight in a really unhealthy way, so when he met the director he “looked like a bear” and was really big but not muscular. I’m guessing he did the same for DK but ran out of time. His physical transformation for the Machinist certainly was one of the more stunning I think I’ve ever seen.
Jared Leto also gained a lot of weight to portray John Lennon’s assassin. Losing the weight he ended up with gout.
She was in Boys Don’t Cry and American Psycho, I’d imagine both of those are more well known than The Brown Bunny.
I think they are all from European movies. Didn’t look them up on IMDB.
Don’t think it counts, as being a masochist he probably would do that anyway.
You mean, like the winner of Miss India beauty pageant, a Miss Universe contestant, and a model for the Revlon cosmetics company?
Can I nominate Joey Tribiani for using a prosthetic foreskin in an attempt to get a role?
(that then fell off during the audition)
American fucking Psycho man. I had such a huge crush on her in that when I first saw it as a kid. Needless to say I was very happy when I’d heard she’d done [del]hardcore porn[/del] an indie art house movie.
She was the central character in Kids, which made a lot of ripples when it came out.
I’m just guessing the OP doesn’t consider porn actors, uh, actors.
That’s where I saw her first as well.
The German/Turkish actress Sibel Kekilli has won 15 best actress prizes at different film festivals. During the hoopla over winning the Golden Bear for her film Head-On her past as porn actress Dilara was discovered.
Now by the standards of German porn, her work was pretty mild, but it was very definitely hard-core, close-up porn.
There have been very good actresses in porn, but very few good directors. Unless you can do absolutely brilliant work on the first take for a director who wouldn’t know good work if it slapped him in the face, you are not going to be good in a porn film. Sibel is proof that having vaginal, oral and anal sex on camera does not ruin you as an actor forever.
It’s definitely meant to signal neurosis on Bridget’s part. Zellwegers weight gain for the role actually put her (on the flawed scale that is BMI) smack dab in the middle of average weight, not overweight by any standard. Bridget was made to look heavier than she is with camera angles, padded underwear, and clothing a size too small. That Bridget was, amongst other foibles, not the most fashionable dresser, was another part of her neurotic character type.
I think the more notable thing is the fact that most Hollywood actresses, especially those under 40 or so, are constantly living on a caloric intake best suited for weight loss, not maintenance, plus several hours of exercise a day, in order to maintain a level of thinness that isn’t natural for their bodies, and it’s expected, applauded, and when anyone attains success while eschewing that body-destroying paradigm, they’re hailed as some kind of physical groundbreaker because they have the nerve to be entirely average in size. (See: Christina Hendricks, Sara Ramirez from Grey’s Anatomy, America Ferrera from Ugly Betty.)
Leguizamo.
Kate Winslett had an interesting scene in Holy Smoke wherein she stood nude and peed on the ground. With her well-known penchant for realism she attempted to do the scene…realistically. It didn’t quite work out…
*“It wasn’t really me weeing. I was rigged. It was so funny. What they did was rig a saline-drip fluid bag at the center of my back. And then there’s this tube, which you wedge up your bum. I wanted to do one take where it actually was me weeing. But unfortunately, when you stand and wee yourself, it just all goes down one side of your leg. And you need to get it down the middle.” **
Elderly pervert that I am, I find the vision of Kate Winslet peeing to be rather…intriguing
*Quoted from katewinsletfan.com
That’s all well and good, but so what? The OP was asking about “outrageous”, not “good”. Most of the things cited here don’t even come near what you can see in pretty much any porn movie.
Well, not the driving-a-nail-through-his-own-penis guy, except I don’t think he really did it for a movie role.