Group Hug

Arwin: Ooh group hug! I love group hugs! Especially with other people! [old lady walks by]
Maddie: Hey lady! Come on, I could really use the heat. [lady walks away] After her! [whole hugging group walks together following the lady]

Arwin: Wow! She's fast!

—The Suite Life of Zack and Cody

The main characters stand in a tight circle and stretch their arms around their two nearest neighbours. Tends to happen fairly often and for lots of reasons such as supporting one character who just went through something difficult or emotional, the final group action before splitting up or carrying out a big plan, or as part of the denouement.

Often times there will be one character who is reluctant to participate in a group hug whenever they occur. That character usually warms up to the idea by the end of the series.

Examples of Group Hug include:

Anime and Manga

Yu-Gi-Oh!^[context?]

Fan Works

If you were cynical you might comment that a group hug is a Succubus's most frequent action in The Return.
In the Harry Potter fic Unforgivable Mistakes, Harry, Neville and three original characters gave Draco Malfoy a group hug after he admitted to having been abused by his father.
In the Harry Potter/Sailor Moon/Ranma ½ crossover The Girl Who Loved, the other Sailor Scouts gave Sailor Moon a group hug when she came back to life after spending roughly a year as a ghost.
Happens in several My Little Pony: Friendship Is Magic fanfics.^[context?]

Film

Punky: [after the convicts won the game] We win! Group hug in the shower tonight!...or not. Or not.

Finding Nemo^[context?]
The Land Before Time Once they finally find the Great Valley.
The main cast gives one at the very end of For colored girls who have considered suicide when the rainbow is enuf. Trust me they deserved it.
Mystery Team^[context?]
Aladdin ends with Genie pulling everybody nearby—including the Sultan and Jasmine's pet tiger Rajah—into a group hug, even growing extra arms to do so. "Mind if I kiss the monkey? *MWAH!* *KAFF!* Ooh, hairball!"

Live-Action TV

NCIS had a particularly heart-rending example. After Franks dies, Tony draws Ziva into a hug on the elevator, and lets her cry on his chest. The elevator doors ding open ... cue McGee and Abby in the exact same position. Cue Tony drawing them into a big elevator group hug. Cue waterworks.
Friends numerous times, but most memorably when Phoebe becomes pregnant, which Phoebe comments can't be good for the baby with her in the middle, so the others have a group hug for her without her.
Red Dwarf: as a way to show Rimmer that he is loved so they can build up his self-esteem and escape. His expression is priceless.
Pretty much ubiquitous on Full House.
The infamous final episode of The Mary Tyler Moore Show featured one.
Teletubbies. Big Hug!
The Suite Life of Zack and Cody episode "Team Tipton". Maddie, Zack, Cody, Esteban and Arwin.
In the pilot episode of Chuck.
In the Torchwood episode "Adam", the eponymous character calls for a "group hug" - as a way of working himself into their memories.
One episode of News Radio.
In Community the study group is fond of this.
Boy Meets World had a few of these, most memorably in the graduation episode when Cory, Shawn and Topanga give Minkus one after they recieve their diplomas.

Professional Wrestling

The MSG Incident
Shawn Michaels, Triple H and The Undertaker at the end of their match at Wrestlemania 28.

Video Games

"Group Hug" is the name of a party healing spell in Super Mario RPG. It doesn't go so far as to portray the hug, however.
This is the second thing the Gorons try to give you when you clean out Dodongo's Cavern in The Legend of Zelda Ocarina of Time. Given that Darunia, their chief, Does Not Know His Own Strength and sends you to the ground with a simple pat on the back, Link wastes no time in running like hell as the Gorons approach.

Web Comics

The Order of the Stick... including one where one of the dumber bad guys tried to join in, but Durkon simply cast "Hold Person" on him (without even breaking the hug).
In PBF TIME FOR GROUP HUG.
El Goonish Shive, in the end of the Painted Black storyline: here and here.
Christmas, 2008 in The Inexplicable Adventures of Bob.

Web Original

The Potter Puppet Pals video "Trouble at Hogwarts" ends with a group hug (or perhaps I should say, a cornucopia of love).
RWBY: In Season 5, Team RWBY does this after finally getting back together.

Western Animation

During the ending of The Simpsons Episode "Homer and Apu":

Homer: Hey everyone, let's all hug Apu.
(Everyone hugs and sighes happily then everyone stops)
Homer: (Checks Watch) We still have some time. Let's all hug Apu again.
(They hug again and THEN the episode ends)

A Tear Jerker moment between the members of Sector V, in the Kids Next Door finale.
Avatar: The Last Airbender: Everything in the description (though Sokka once had to be told to shut up and join in).
- Earns extra cuteness points when Appa just closes his eyes and shoves his huge face into the huddle, or when Zuko is first included in the group hug.
Teen Titans

Starfire: Let us initiate a group hug!
Raven: Pass...

The puppies in One Hundred and One Dalmatians: The Series.
- How do puppies hug, exactly?
  - This troper is imagining a dogpile. A hundred and one Dalmatian puppies, piling on top of each other with those adorable doggy-smiles and floppy ears.
  - With the one on bottom getting crushed to death by the weight of 100 other dogs.
Sonic Underground had one of these, with Sonia announcing "Group Hug!" at the end of the second episode.
Tuck loves to call for one of these following the successful completion of a mission of on Wonder Pets.
Subverted in The Mighty Ducks. After an episode in which Duke's criminal past had caused some tension, he assured his team he could never stay mad at them and called for a group hug...so he could steal their equipment.
Ben 10 Alien Force ends shortly after one of these with Ben, Gwen, Kevin, and Max after Ben defeats Vilgax, possibly for good.
Jimmy of Jimmy Two-Shoes loves to do this.
Total Drama Island has one of these when DJ is eliminated. Everybody joins in on it, even Heather.
The Boondocks has the Freemans doing this in Season 3's finale, "It's Goin' Down".
Pops up from time to time in My Little Pony Friendship Is Magic.
Parodied in Family Guy:

"We're all such good friends! You can tell by the way we're pressing our faces together!"

Grouchy gets hug-mugged by a group of Smurfs at the end of The Smurfs episode "A Hug For Grouchy" and really hates it!

Real Life

Sports teams after a big victory.
After getting drunk together ... "I love you guys!"