Cool Uncle

"Hey kids! Uncle Bob's here!"
"Yay! Uncle Bob!"

Lots of fictional families seem to have that one uncle that all the kids just love. Most often, the Cool Uncle is a young bachelor who has no intention of settling down any time soon, though he may have a girlfriend. He may travel a lot and wow the kids with stories of meeting celebrities and roaming the world (and if so, he always brings back the coolest souvenirs, which he naturally gives away as presents). Or he may be well-off and spoils his sibling's kids whenever they're together.

Regardless, he will often be secretly be envious of the stability and loving home life that his brother or sister enjoys, even as he boasts of his own independence. The uncle may also be the Black Sheep of the family.

This trope is usually male, but the role will occasionally be taken on by an aunt.

Examples of Cool Uncle include:

Anime and Manga

Main character Yuuta Segawa of Papa no Iukoto o Kikinasai!, who all three of his nieces look up to (one of which even has a crush on him), especially when he adopts them.

Comic Books

In the Fantastic Four, Reed and Sues' children consider Johnny to be a cool uncle since he's a superhero that sets himself on fire. Ben also gets this treatment although he's not related.
Spider-Man's own uncle Ben was a pretty cool guy since he fought in World War II and shaped Peter into the man he is today.

Fan Works

In the crossover fic Nexus, Dante is certainly because it's well... him. Though he would argue that he sees himself as more than just an uncle.

Film

Uncle Charlie in Alfred Hitchcock's Shadow of a Doubt.
Uncle Buck, starring John Candy.^[context?]
That's how young Simba saw Scar in The Lion King. Scar took advantage of this and tried to send Simba to his death.

Literature

Uncle Press in The Pendragon Adventure.
Walker Boh of the Shannara series served this role to Par and Coll Ohmsford, albeit in a more cranky manner than most.
Joe in The Book of Joe is one. And is called out on it for being a little too cool/a bad influence, by his brother.
In The Trolls, Aunt Sally is the female version for the kids.
- Great-Uncle Louis thinks he's a Cool Uncle, but only Robbie really thinks he is.
Nancy and Peggy's Uncle Jim, also known as "Captain Flint", in the Swallows and Amazons series. He lives on a houseboat, owns a Pirate Parrot, and has travelled all over. A great part of the first book revolves around his nieces starting a private war with him, since he's taken up writing and become distant, therefore, in their minds, ceasing to be cool.
Discworld: City ruler Lord Havelock Vetinari is the epitome of cool and cunning. But from the novel Night Watch onwards, the character of his only living relative, the aunt alluded to in Guards! Guards!, is opened up a little: it is hinted that Vetinari learnt a lot of his skills from Auntie Bobbie (Lady Roberta de Meserole), who is a political manipulator, a Seamstress where she needs to be, possibly one of only a handful of female Assassins, and a lady of guile, insight, cunning and wisdom. She has certainly raised Havelock in loco parentis after the undetailed death of his parents. A second wise woman in Havelock Venturi's life, an aunt-like character, has been the vampire Lady Margollota (although some interpretations hint at a sexual relationship.)

Live-Action TV

Everybody Loves Raymond: In one episode, Raymond laments the fact that Robert is always willing and able to play with Raymond's kids when he comes over, never seeming to be too busy or too tired to do so. When Robert discovers this, he explains that he's only able to do it because he only ever sees the kids for an hour or so at most. Raymond, meanwhile, cares for his children effectively all the time, and shouldn't be ashamed that he lacks the energy to "Play Monster" with them all day.
Rachel in Friends is delighted when Ross' young son Ben starts calling her his 'Fun Aunt Rachel' and being thrilled to see her.
Family Ties had Uncle Ned, played by Tom Hanks. He was really cool, but he had a drinking problem.
Uncle Jesse from Full House.
Joss Whedon has said that in Buffy the Vampire Slayer season 7, Faith was a Cool Aunt to the Potentials, whereas Buffy was the mom.
Fester in Wednesday. He's nutty even by the standards of the rest of the family, but as of the end of season one, he is the only character who has managed to make Wednesday smile.

Music

In Jimmy Buffett's song "The Pascagoula Run", he sings about his "black sheep" Uncle Billy, who had made it rich while traveling around the world. When Billy came back home to Mississippi, he immediately went on a 24-hour bar-hopping run to all his old haunts and invited his nephew Jimmy to come along. According to Buffett, this all actually happened back when he was 17.

Billy pulled in in a Jaguar
Red convertible '65
Headed home to Mississippi, he'd been around the world
That black sheep uncle of mine
His ship had come in, he was looking to sin
Singing his own song
When he yelled from the drive, my heart came alive
"Jimmy boy come along"

Newspaper Comics

For Better or For Worse: Elly's musician brother has made a few appearances, and the kids, Michael and Lizzy, just adore him. Hilarity Ensues when he attempts to take the kids off the parents' hands for a night and he wears himself out trying to get them to bed.
Scrooge McDuck may count to Huey, Dewey and Louie.

Tabletop Games

Found in the Call of Cthulhu campaign The Fungi from Yuggoth adventure "Mountains of the Moon". An NPC named Victor recognizes one Player Character. He was an old friend of the PC's father, and the PC remembers him as "Uncle Victor", a warm, good-hearted man (even though Mom didn't seem to like him).

Video Games

Mario Auditore in Assassin's Creed. He gives Ezio money and a place for his family to stay, and inducts him into the Assassin's order.
In Shantae, the heroine's Ditzy Genius Uncle Mimic.

Web Comics

Subverted with crazy uncle Duncan in The Perry Bible Fellowship here.
Rayne in Least I Could Do gets along very well with his niece and is always willing to play with her. He tried to call out his sister on not spending more time with her daughter, but she responded that Rayne has it easier since he doesn't have any of the responsibility that comes with being a parent. Rayne actually acknowledges this.

Western Animation

Uncle Iroh was this to Zuko during his childhood in Avatar: The Last Airbender. As he aged, Zuko treated his uncle as more of a buffoon as he (Zuko) came more and more to resist Iroh's guidance—which encouraged Zuko to reject his father's philosophies about honor (along with Iroh's tendency to distract Zuko from Wangst via Obfuscating Stupidity). Toward the end of the series, Iroh again becomes Zuko's Cool Uncle.
In Taz-Mania, Taz and his siblings have an Uncle Drew whom they adore. Maybe because he's an Expy of Bob Hope.
On Daria, Daria's Aunt Amy is a Cool Aunt.
Uncle from Jackie Chan Adventures, duh.
Scrooge McDuck, Donald Duck's wealthy uncle and Huey, Louie, and Dewey's granduncle. When it comes down to it, the triplets also think the world of "Unca" Donald himself.
- And Professor Ludwig von Drake, Donald's other uncle, who is a scientist.
Scrappy-Doo thinks of Scooby-Doo as a Cool Uncle, despite Scooby's cowardice.
On The Simpsons the titular family has "Uncie Herb".
- Milhouse also has a cool uncle who took him in when Milhouse thought his parents had died.