Top 10 Times the How I Met Your Mother Cast Couldn't Keep a Straight Face

“Bagpipes”
In this episode, Ted grows suspicious when Barney and Robin play the picture-perfect couple. But, as it turns out, all is not well in paradise. They’re actually going out of their way to avoid conflict, tiptoeing around their frustrations. But then fate, in the form of a chairlift, traps them together, leaving them no choice but to confront all those pent-up annoyances. In a hilarious blooper, the couple dives into a heated, seemingly adlibbed argument about their intimate life. Neil Patrick Harris throws out a remark that breaks his scene-mate. Of course, it isn’t the only occasion NPH cracks Cobie Smulders. But what did he say?!

“Say Cheese”
Lily's birthday sparks excitement akin to a child on Christmas morning, and Marshall's more than happy to indulge her. Throughout the day, Marshall showers Lily with numerous surprises, including a personalized song. While Lily and Ted squabble over the woman he brought to the party, Marshall, the maestro, tries to transform discord into harmony, and yes, there are parts for everyone. While giving Robin her instructions, we see Barney grin beside him. Or is it NPH himself enjoying the amusing spectacle? Either way, it's hard to tell where the character ends and the actor begins. In the end, Barney bogarts the melody entirely, bringing some levity to a tense moment.

“Last Words”
In Season Six, Marshall faces an unthinkable loss: his father’s sudden passing. The subsequent episode unfolds at Marvin Senior’s memorial service, where the family reflects on their final words with him. Marshall worries his last conversation with his dad wasn’t meaningful enough, and his friends try to console him. He stops them and makes them understand his feelings by telling them to imagine themselves in his place. In the episode, it’s a real tear-jerking moment. Yet, in a blooper, the emotion is shattered by a ringing phone. Jason Segel jokingly vents his frustration, only for someone off-camera to reveal it’s his phone causing the disturbance.

“Showdown”
As a child, Barney asked his mom about his dad—she told him it was Bob Barker. Eager for a father figure, he believed her. And where better to have the grand reunion than on national television. In the scene that made it to air, the emotion in Barney’s voice and that perfectly timed catch in his throat definitely had us snickering. In the gag reel, the laughter proves to be contagious. With each take, Barney’s emotion escalates, making his co-stars burst into giggles. Nothing seems to curb the laughter, either. And who could blame them? NPH’s comedic brilliance shines through, leaving us all in stitches.

“Matchmaker”
In season one, Barney tricks Ted into visiting a matchmaker with him, but of course, his intentions are far from honorable. When they meet Ellen, the owner of “Love Solutions,” Barney paints an exaggerated picture, trying to appear like the perfect partner. We imagine he requires his wingman, nay, his bro, to play along to pull off his act effectively. But is that what Ted’s doing? See for yourselves. Either Barney’s plan is so ridiculous that Ted can’t help but smirk, or Josh Radnor, the actor, finds the scene absurd. We’re not saying that Ted ruined Barney’s play— after all, this isn’t Ellen’s first day on the job— but it probably didn’t help either.

“Stuff”
Ted and Robin bring an argument about gifts from exes to their friends, sparking a flashback to the 2005 case of Lily versus Joey Buttafuoco pants. In the flashback, Marshall tries to win over his friends with the colorful garment but fails. Maybe if he’d stuck with his dance from the outtake, he might’ve had more votes on his side. Who wouldn’t laugh watching a friend do a backward running man in parachute pants? Smulders tries to hide her amusement, Radnor is visibly entertained, and even Segel can’t help but chuckle. He struggles with his lines, eventually giving up and starting over, adding to the hilarity of the moment.

“The Mermaid Theory”
Remember Barney’s Mermaid Theory from Season Six? Keeping that in mind, Marshall and Robin hang out one-on-one, just as friends, of course. After Marshall shares Barney’s theory with Robin, he starts picturing her as a manatee. And well, this blooper shows why you don’t see too many manatees hanging out at bars. Kudos to Smulders and Segel, who try to keep the scene going. But watching Smulders try to lap up her drink like a cat is hilarious, and her side-eye to the camera is priceless. You can hear the crew cracking up in the background, bringing the fun from the set straight to our living rooms.

“The Rough Patch”
Ted and Marshall stake out a diner to spy on Barney and Robin. Of course, they’ve ordered cake as part of their cover, setting the stage for this relatable blooper. Segel sneakily bites into the tempting slice, and honestly, who could blame him? The allure of that cake would have tested anyone’s willpower. Radnor notices and tries to muffle his laughter behind his menu. They soon dissolve into two mischievous school kids unable to contain their giggles, even when they know they’re up to no good. Indeed, they get a humorous telling-off, but come on, it’s cake! And sometimes a little mischief and cake are the perfect recipe for laughter.

“Definitions”
Ted’s stressing about his new gig as an architect professor, and what’s Barney up to? Not defining his relationship with Robin. Repeatedly. One night, Ted wakes up from a nightmare and catches Barney snooping in his bedside table. Ted tries to tell him about his dream, but Barney isn’t interested. In the blooper, when Barney asks where Ted keeps his protection, Radnor ad-libs a line that suggests things are about to get spicy in the bedroom. NPH rolls with it, and you can hear the crew cracking up in the background. These moments are like a backstage pass to their awesome chemistry, and it’s just pure entertainment.

Before we unveil our top pick, here are a few honorable mentions.

Barney’s Enthusiasm Breaks Them Both

Jason Segel Really Goes for It & Alyson Hannigan Seemingly Isn’t Ready for It

Who Knew Laundry Could Be So Hilarious?

Segel Really Knows How to Keep a Joke Running

Lily Is Very Passionate That Barney Doesn’t Lie to Nora

“Game Night”
In this hilarious blooper, Ted tries to share an embarrassing story to avoid revealing another secret. The episode revolves around a baffling game called “Marshgammon,” invented by Marshall, to probe Ted’s new girlfriend, Victoria. As Ted narrates an incident involving a guy with unusually sharp toenails, Radnor messes up his line, creating a hilarious anatomical mix-up. It’s so funny that everyone bursts into laughter. Every time they try to get through the dialogue, the thought of the blunder triggers a delightful domino effect that extends to the audience. We never actually get to hear the end of the story, but this outtake more than makes up for it.