Japan and Greece from Axis Powers Hetalia, who wind up having sex mainly because Japan ranked last place in a sex frequency poll and Greece (in first place on the same poll) decides to teach him how to enjoy doing it more. Though there are hints that Greece harbors genuine romantic feelings for his friend and it hasn't escaped shippers' attention that Japan doesn't seem to be the kind of person who'd sleep with someone on a whim alone.
In ...Virgin Love, Kaoru and Daigo have what is supposed to be an anonymous one night stand, but then meet again at work. Kaoru doesn't want a relationship but thinks the sex is too good to give up so he and Daigo become sex friends instead. Daigo quickly falls for Kaoru.
This trope is possibly the best category for Lupin III and Fujiko. Lupin believes they're soulmates (not that it prevents him from hitting on other women), and Fujiko prefers "Fuck Buddies" (except without the sex). Which means they wind up here, somewhere in the middle.
More accurately, Carly is scared of a Relationship Upgrade because she's used to her and her brother wrecking their relationships and never speaking to the other person after they break up, so feels if they keep it casual, she can avoid hurting Freddie whilst still giving him what she believes he wants most. Freddie gets concerned that because Carly doesn't want to tell anyone, and that they haven't slept together again, that Carly thinks it's a mistake. It's also something of a deconstruction of the Girl of the Week format and how a real person would be affected by seeing and being part of relationships which seem to only last one night, days or barely weeks.
This is the relationship between Jia-Chien and her ex-boyfriend in Eat Drink Man Woman. They get together regularly to chat and to knock heels, but otherwise prefer to see other people.
Also Tomas and Sabina in The Unbearable Lightness of Being.
In Jackie Brown, Louis and Melanie have this sort of realtionship. However, Melanie is a bit of slut, although she seems to like Louis- he's an old friend whom she hasn't seen in a long time. This all goes to shit when Louis shoots her for trying to take the half million for herself, plus being overly annoying, even for her.
In Vanilla Sky, the main character has a "Fuck Buddy" relationship with a model. The "buddy" in question takes things a little more seriously and when she finds out the true nature of the relationship, it doesn't end well.
In the TV movie Stone Cold, Chief Jesse Stone and Abby have this kind of relationship until she's murdered by a serial killer.
Ted and Annie in Bridesmaids — she hates him, but the sex is great. When she "dumps" him, he drives off with the line "you're no longer my number three!"
The Guardian: Fisher, one of the Coast Guard rescue swimmer trainees starts hooking up with a school teacher named Emily. He tells her the he can do casual, but at the end, after he's finished training, he comes to her and says, "I can't do casual." Fortunately for him, she agrees.
French Sci-Fi novel Malevil features Emmanuel and Birgitta. Emmanuel is a rancher and she was a German girl who would spend time in town and work for his uncle. After the uncle's death, she turns her eye on Emmanuel and makes their relationship very clear: recreational sex and nothing more. They have a happy affair for a while before she leaves for home and writes to announce her marriage. Emmanuel takes it harder then he should have, and has to remind himself of what their relationship was.
The titular Fire and her childhood friend Archer from Kristin Cashore's Fire.
Spoofed in parody self-help book Oh the Humanity, in which all of the Unreliable Narrator's relationships like this supposedly end with the sexual component curtailed for fear of "damaging the friendship". The actual phrases they use?
I never want to do that again. You have the muscle tone of gravy, but your caress has all the tenderness of a nail gun. I'd rather eat you - literally, cook and eat your flesh - than find myself in your arms again.
Spendwell and Thorn in Frostflower and Thorn. Played straight without romantic complications, as Spendwell comes to entertain feelings for Frostflower and Thorn plans to get him off it by arranging a match between him and another young lady. In fact, I'd hesitate to even call them friends if they hadn't shown obvious caring for each others' welfare.
Brad and Denise end up in this trope towards the end of season 2 of Boston Legal. Possibly lampshaded with Denise repeatedly claiming they are "only friends... with benefits."
But the Friends With Benefits does lead to the two eventually getting married and having a kid.
At one point on Boy Meets World after Shawn and Angela break up they try to have no strings attached sex but Shawn gets too emotional about it and Angela calls it off before they can even get past the makeout foreplay.
On Community this becomes the eventual arrangement between Jeff and Britta.
On Farscape Aeryn suggests she and John have one of these. Because he's in love with her, he turns her down.
It should be noted that this verges upon being a Hat for the Peacekeepers, as their SOP requires that sex remain strictly recreational or procreative (when assigned). Fw B is their default relationship state.
Aeryn's mother was ordered to kill her lover (and Aeryn's father) when their relationship was discovered.
Monica and Richard attempt this in Friends after their breakup, but while he takes the new situation to the letter, Monica starts falling back in love. It culminates with her preparing a sexy surprise in his bedroom and him coming home with another sexual partner. Awkwardness ensues, and eventually Monica figures out it can't work.
Also, Monica and Chandler's romantic relationship started as no-strings-attached sex (only in London, mind. Then... only while on London time. Then, just 'goofying around'...then a relationship...then...ok, ok safe to say it ends with them Happily Married. They are the poster couple for Sex Equals Love after all).
Interestingly, Lisa Kudrow and Matt LeBlanc wanted this for Phoebe and Joey with no intent to turn it into a relationship later on, but the executives backed out.
On How I Met Your Mother Barney and Robin have this sort of thing going for a while. Then Lily holds them prisoner until they decide on being either friends or boyfriend/girlfriend. They eventually choose the Relationship Upgrade.
Ted and Robin had this type of relationship in "Benefits", as part of the writers' continuing efforts to have them hook up at least once a season. In a neat little twist, despite a few worrying implications of Sex Equals Love, neither of them ends up being hurt by the arrangement: Barney is.
When Lilly's dad and Marshall's mom hook up they refer to it as Family with Benefits. Squick
What Dyson and Bo try to have in Lost Girl, but they both develop feelings for each other.
Jerry and Elaine try to do this on Seinfeld, "The Deal". They propose a set of ground rules by which they can have both "this" (with a gesture at the space between them as they sit companionably on the couch) and "that" (pointing towards the bedroom). They soon find that it doesn't work out without having "this, that, and the other"—i.e., a full romantic relationship.
It's subverted on Seinfeld, with George telling Jerry An Aesop message about how "it can't be done—" and that people have tried to do it it throughout history, to no avail. Naturally, he's proven right.
If you didn't romance either Garrus or Tali in Mass Effect 2, then its heavily implied that they become this near the end of 3. Tali even outright tell Garrus "I'm just using you for your body." but its unclear if she's being serious of just joking.
Combined with Puns in the Portal 2 achievements. There's an achievement called "Friends List With Benefits" for hugging three people on your Steam friends list. Although hugging is the closest thing ATLAS and P-Body get to romance or sex, at one point GLaDOS asks the bots if they know what could happen as a result of hugging...and makes it sound for a moment like it could result in STD's.
In The Sims 3, it's possible to make your Sims be friends with benefits, and will react slightly differently after woohooing. In fact, unless they choose to go steady, they can have sex without actually considering themselves in a romantic relationship. This is quite different from The Sims 2, where just chatting each other up can result in them basically making it official, and you need a Game Mod for them to ever have sex outside of a relationship.
It's implied in a guest strip that their intimate moments involve intense amounts of hostility. Which makes it better.
Though it's obvious Faye thinks of it as more than just random sex: when Sven sleeps with another girl she gets all heartbroken and stops seeing him at all. Sven seems to have become very attached, though he seems to be telling himself it's just the sex.
Candi had a few characters trying this out, but it eventually gets too complicated.
In this comic, Desirae of Alone In A Crowd suggests this to her niece Sara and her best friend Marty much to their mutual annoyance.
Nanase: Besides, you and I know this relationship was little more than two good friends giving each other privileges.
Elliot: I never liked to think about it that way.
Nanase: But that's what it was. Name one romantic thing we ever did together.
Elliot: Does making out in the car outside the movie theater count?
Most notably, Miriam and Steven, post-breakup, in Out There. A few other pairings have taken place (or are implied to have taken place) as a part of the back story: Sherry and Steven, Miriam and Wally, and possibly even Miriam and Sherry; there is also a reference to a Friends With Benefits relationship between Miriam and a character named Carlos in one of the flashback stories in the third Out There book.
Played for drama since Zeke only admits his love for her after she's murdered.
This was the premise of College Humor's former show "Full Benefits", where this sort of relationship occurred between fictionalized versions of staff members Sarah and David. Later they tried to "take it to the next level" by becoming romantically involved as well.
In The Wulf Archives, Wulf has a few serious lovers, but the other women in his life are this trope, who like him and make no demands on him beyond an open invitation to their beds when he comes around.
The Guild has Wade and Riley. Surprisingly, when Codex finds out that they're only "<bleep> buddies", she no longer sees Riley as a rival for Wade's affections. This stops when Riley starts sleeping with Zaboo, but by that point Codex has realized that Wade is a Jerk Ass.