Danny & Oswald going shopping with their race money on Season 2.
Season 12, Donald, a 68-year-old man, pole-vaulting a ditch in his underwear
Dan's marching "prowess" on season 13.
Inaudible dialogue is often subtitled to make things easier for the viewers, but when Season 16's Jordan (the female one) attempted to speak to teammate Jeff with a mouthful of baguette, the subtitle simply read "??????????"
Loud and proud virgins Millie and Chuck providing numerous Double Entendres, the best being Chuck's bout of claustrophobia in a race car: "I'm feeling hot! Hot and tight!"
Terrence, already infamous for his less than masculine behavior like whining endlessly about bumping his head on a cab trunk and insisting his girlfriend Sarah blow on it, asks her late in the race "Who's my girl?" She instantly replies "You are! No, I am!"
Ken and Gerard in season three, the Crowning Team of Funny. Perhaps the best part is when they arrive second to last and burst out laughing in the middle of Phil's trademark Dramatic Pause.
Flo's ridiculous, over the top meltdowns (with Zach being her beleaguered team-mate) and Teri and Ian's constant but playful bickering in addition to Ken and Gerard made Season 3 arguably the funniest one ever.
This gem from Eric in All-Stars, after Dustin & Kandice had to eat tons of Kielbasa:
"Ladies and Gentlemen: Miss California!"
Dandrew can either come off as one Crowning Moment of Funny after another or one What an Idiot after another. The two even pointed out how much they flat out sucked at the race and said there needs to be a YouTube compilation video of all their mistakes. And there is, so chances are they were laughing at themselves.
In season 14, one of the tasks involved carrying 50lb cheese wheels down a very steep hill. Unfortunately the equipment provided was (probably intentionally) really really shoddily built, so just about everyone either broke them or fell and broke them. People were sliding on their rears down the hill, especially since it was slippery, or were just rolling the cheese down the hill. The episode quote literally came from one contestant:
"Don't let a cheese hit me!"
In The Amazing Race 17, Stephanie finally gets tired of her boyfriend Chad always blaming her for the things that go wrong for them on the race. Then, later on in the race, Chad proposes to her... and she accepts!
Stephanie: I just think that's really shady.
Nick and Vicki having a clue eaten by a goat.
Season 11 (All-Stars), leg 5: After a Detour which included hand-shoveling charcoal into bags, Oswald and Danny (along with the other teams that took that task) wound up with filthy hands. They then attempted to hug Phil at the pitstop and ended up chasing him for a while.
In season 5, revealing that Brandon and Nicole, the annual team who can't shut up about their religion, are basking in the heavenly glow of...an airport's arrival/departure monitors.
The third leg of the first season of TAR Latin America had a Roadblock that took place in a vineyard. The team member had to search through the large grounds for hidden boxes that contained wine bottles, then they had to take 18 bottles to the front area, label them correctly and box them. Despite the cool weather, the sun was blazing and those who performed the task were exhausted with so much running and searching for the very well hidden bottles. And what were their teammates doing? Standing in the cool shade of the vineyard's main building, sampling wine and cheese and toasting each other like they were in some kind of posh get-together, and some of them could not help teasing their tired teammates over it.
Season 18: everyone running around an Australian mining town in kangaroo costumes, completely weirding out the locals they ask for directions.
Half of episode 4, with Kent and Vyxsin screwing up everything they touch (including managing to lose their passports twice in one leg), Ron wanting to stop and eat every thirty seconds to Christina's dismay, and Flight Time being completely unable to guess his Zodiac sign.
All the teams arrive at the next clue box area at the same time, and the Globetrotters shout that they've found it, causing everyone to race around also trying to find it...except it was a prank, as they won't be able to get inside to get the clues until the next morning.
Mallory doing a task involving manure, wearing the exact same outfit she wore for the big manure task of her previous season. Unsurprisingly, she then says she's getting rid of it ASAP.
Zev & Justin getting Brazilian Body Waxed in the Penultimate leg, as they were the hairiest team up to that point (even pointed out by another team). They even said themselves: "this is not a leg for us".
Earlier, Zev & Justin were stuck in a Fondue eating challenge. As Nausea Fuel as it was, the camera focuses on Zev making a very funny face as Justin goes to hurl.
The Amazing Race Australia, episode 1; half the teams are neck and neck at the final task, counting money and trying to find the right amount...when an ice-cream kart inexplicably shows up, with the tune playing loudly and annoyingly to the only team near it, Mo and Mos. It's funnier in the actual episode than on paper, really.
Mo: "Yeah mate, just torture us."
Hilda, from Season 4 of The Amazing Race Asia, borders between The Load, The Scrappy, and one of the funniest contestants that season. Highlights include being forced to repeatedly climb the steps of the Batu Caves when she keeps on writing down the wrong number of steps at the Roadblock, and convincing her husband to stroll with her to the pitstop on the second episode...with a team right behind them. Watch it.
In Season 20, leg 2: Vanessa mistakes the chasqui who would be giving out the next clue for a dog (and then realizing that it's not bilingual). She also stated that the dog is "giving" out a clue by moving around a stone.
Jo, while doing the frozen waterfall climbing task in Australia 2, said she was going to draw inspiration to drive her picks into the ice wall by imagining it was Paul's face. She then yelled at Paul, who was getting ready right next to her, to make sure he had heard her. Cut to Paul and Steve in their post-leg interview, Steve laughing his ass off while Paul said:
Paul: Gee, that was a nice thing to let me know.
First task in Amazing Race 21, they must play ping-pong against a ping-pong champion. She would switch to various items after they lost one or two matches, and against one team, she used the clue.
James and Jaymes manage to walk right to the pit stop before finding a woman using an abacus. They even follow Caitlin and Brittany, see them at the pit stop. James was priceless, as they immediately turn around, since they went the wrong way
"Oh no that's the pit stop!"
In episode 3 of season 21, Nadiya hitting her face on the camera while leaving the U-Turn station.
This quote from Season 21, leg 4:
Brent: Josh used to sew a lot of his costumes when he was a drag queen.
Followed by Jaymes & James asking Josh what his Drag name was (Aquadisiac) and Josh commenting that a certain partner is going to be sleeping on the couch tonight.
The bamboo Detour in leg 5 of Season 21, which involved the teams repeatedly smacking locals with their bamboo poles as they turned corners.
Australia 2 episode 4. A number of teams know they are in last place getting to the mat and their reactions, most funny though is the 2nd last team.
Season 13, the Pit Stop Greeter at Humayun's Tomb in Dehli was the tomb's gardener. Unlike every other greeter in the show, he was not standing next to Phil, but instead watering the lawn, and would run up next to Phil every time a team would run up to the mat.
Listening to the teams trying and badly failing to pronounce the names of certain of the locations visited on the race
Season 22, Jessica & John just randomly wandering into some guys backyard in Bali and copying what the guy was doing, thinking it was the Detour.
Chuck thanking a Vietnamese person with "mucho gracias."