No Strings Attached

No Strings Attached is a 2011 romantic comedy directed by Ivan Reitman (Ghostbusters, Dave) and written by Elizabeth Meriwether. The story is about two longtime friends, Emma (Natalie Portman) and Adam (Ashton Kutcher) who decide to become Friends with Benefits.

Tropes used in No Strings Attached include:

Anguished Declaration of Love: Emma does this at the end of the film.
Anything That Moves: Adam's dad, Alvin.
Beta Couple: Patrice and Eli, shown having a normal courtship and relationship in contrast to Emma and Adam.
Black Best Friend: Wallace, the man who had the bar.
Catch Phrase: In-universe example, Adam's Dad was once the star of a fictional comedy show called Great Scott. Thus everywhere he went, everyone asks him to say "Great Scott!" for them.
Defrosting Ice Queen: Emma is vehement in being cold and distant to Adam, but the more time she spends with him, the more she realizes that isn't who she wants to be all the time.
Dueling Movies: Friends With Benefits runs an incredibly similar plot to this film as you might have guessed, releasing six months after this one. And for an added bonus, the female lead of that movie is Natalie Portman's Black Swan co-star, Mila Kunis, who also played Aston Kutcher's girlfriend on That '70s Show. The male lead, Justin Timberlake used to be in 'N Sync, which once released an album called No Strings Attached.
Everybody Has Lots of Sex: Played straight from the first scene to the closing credits.
Executive Meddling: Natalie Portman spoke in one interview that studio execs refused to let her improvise anything. The thinking was since she's mostly been in drama films, she wouldn't know how to be funny; despite the fact that she appeared on Saturday Night Live once, and her role in Garden State was comedic. Natalie only got one improvised moment in (the bit with the 3D Glasses), and it's possibly one of the film's funniest moments.
Fan Service: Literally one second of Natalie Portman's butt.
- Plus several minutes of Man Service with Ashton Kutcher in nothing but a tiny towel covering him up as well as close up of his butt. Even one of Emma's friends were impressed.
Foot Focus: There are a couple times where Natalie's bare feet are right up at the camera. Such as when her underwear is getting pulled off. Plus, she's barefoot on the movie poster. In some versions of the poster, the title doesn't obstruct her feet.
Friends with Benefits
The Fun in Funeral: Emma hinted with Adam about going with her to something stupid the day before. So he shows up in a Michigan bright yellow hoodie and shorts to her dad's funeral.
Girl-On-Girl Is Hot: Two lesbians fall in love right in front of Adam and start making out right on top of him. He even takes the time to put his head in between the two to take a picture to make it look like he's having a threesome since Emma refuses to have sex with him unless he does it with someone else.
Gold Digger: Vanessa, after she and Adam broke up. She cheated on him with his dad and told him straight up that she wanted to marry, have a baby and thus become Adam's stepmom. Thankfully, this plan was adverted at the end of the film.
Has Two Daddies: Played straight with one of Adam's best friends.
Hospital Hottie: Emma.
Intertwined Fingers: Emma and Adam do this in the very last scene.
Love Father, Love Son: Inverted as Adam's father keeps dating his ex-girlfriends/women who fell for him.
Mood Whiplash: A big one when Adam confesses that he loves Emma and she responds by repeatedly punching him in full view of public. A police officer has to come by and break them up.
Naked First Impression: Adam, after a day of drinking away his sorrows he finds himself on the couch where Emma and her three friends stay at with only a hand towel over his area. Even better, according to Emma, he threw off all his clothes and danced around, waving his penis around the night before.
Nice Character, Mean Actor: In-universe and played straight. Everyone loves Alvin, but in real life, he treats his son Adam like crap like dating his ex-girlfriend Vanessa.
No Social Skills: Lucy. Dear God, Lucy.
One Head Taller: Adam and Emma (Ashton Kutcher is 6'2,5, Natalie Portman is 5'3).
- They even lampshade this at one point.
Pair the Spares: Almost every character is shown to be in some kind of relationship at the end of the movie.
Product Placement: Adam and Emma proudly use Trojan condoms. And iPhones.
Romantic Runner-Up: Lucy.
Sesquipedalian Loquaciousness: Emma and her fellow hospital coworkers/friends use these in quite a few jokes. Anytime Adam tries the same thing for them, they always accuse him of looking it up to which he humbly acknowledges so.
Sex Montage: Watch Ashton Kutcher and Natalie Portman merrily get it on all over the place with background music!
Shout-Out: High School Musical, anyone?
- More of a Glee vibe with regards to the musical high-school set TV show that Adam works for.
She Is Not My Girlfriend
This Is for Emphasis, Bitch: Emma drunkenly throwing two girls out of Adam's house.

You look like a pumpkin, bitch!

A Threesome Is Hot: Zigzagged. Initially two girls fall in love sitting on either side of Adam, and he just looks like he's caught in their moment. Then he takes them back to his place but when he goes in for a kiss one of them pushes him away. All of this only to serves to reinforce Emma's jealousy of course and leads to a Crowning Moment of Funny as she drunkenly kicks them out of his house.
Wild Teen Party: In the beginning at the University of Michigan, where plenty of people are having sex with Anything That Moves.