The Bat-family starts with patriarch Bruce Wayne aka Batman, theBadass Normal. He's adopted four sons and a daughter: Nightwing aka Dick Grayson, the original Robin, and the undisputed leader of a generation of superheroes; bitter middle son Red Hood aka Jason Todd (formerly the second Robin), with Batman's badassery and none of his mercy; Red Robin aka Tim Drake (the third Robin), following in his adopted father's footsteps so closely that it's difficult to separate the treads; the most recent son, Duke Thomas from We Are Robin who has light based powers and protects Gotham during the daylight; Cassandra Cain, Batman's sole adopted daughter, Batgirl and the world's single best martial artist, who can wipe the floor with all five of them. Probably at once.
Then we have his biological children: Damian Wayne who is badass by default; Terry McGinnis as the son who eventually goes on to not only become the Batman but the leader of the Justice League; and the Huntress, Helena Wayne, Batman's AU daughter with Catwoman who was too badass to be 'Bat-anybody' after her mother's death.
In terms of extended family, Kate Kane, the second Batwoman, is Bruce's first cousin and Damian's first cousin once removed. Bette Kane, AKA Flamebird and the original Batgirl, is also one of Bruce's cousins.
You've also got Fire-Forged Friends, like Barbara Gordon, the second Batgirl and hacker supreme Oracle, or Stephanie Brown, the fourth Batgirl/fourth Robin and Spoiler, who won't stop being a superhero. Not even if you ask, tell, torture, or otherwise encourage her otherwise. Even the dog, Ace, can fight crime. That's not counting badass parents, children, servants, love interests, and baby mommas like Huntress, Catwoman, the first Batwoman (Kathy Kane), Commissioner Gordon, Talia al Ghul, and Alfred. Any one of whom could kick your ass so hard that it turns inside out. Oh, and Superman's always willing to babysit. Even though technically, only Batman, the Robins (sans Steph), Cass, Kate, and Bette are related, crime fighting brings them all together as a family. Gotham wouldn't be the same without any of them.
There is also Harper Row, the bisexual heroine Bluebird, her brother Cullen and people like Dr Leslie Thompkins. And don't forget other allies like Harold Allknut, Jean-Paul Valley/Azrael, Michael Lane/Azreal, Gavin King (the fallen hero Orpheus) and the Clover siblings, Hank and Claire who were Gotham and Gotham Girl respectively.
Blue Beetle: Even though Jaime Reyes is the only one with powers, his entire family have done badass things. His mother talked down Guy Gardner, and his father beats Mooks with his cane. According to Fanon, his little sister is going to be a Green Lantern one day.
Booster Gold: Booster Gold's family as him, his sister, his many greats grandfather, and his son, Rip Hunter are all superheroes and time masters.
Doom Patrol: The Reynolds family from ''Doom Patrol (2016), literally level up in Una-Kalm: Valeria becomes an archer; Lucius becomes a mage; and Samuel becomes a tank.
The Flash: The West/Allen family has Barry Allen, Wally West, Bart Allen, and a whole slew of adopted speedsters like Johnny Quick, Max Mercury, and the original Flash Jay Garrick. Barry's been dead for twenty years, but he doesn't let that keep him down. At least until Final Crisis, wherein Barry returned to life.
This is without even taking into account the evil branch of the family tree, the Thawnes, who might be evil and psychotic, but are definitely badass. You've got Barry's Evil Twin Malcolm Thawne, better known as Cobalt Blue, twenty-fifth century descendant Eobard Thawne who became the Reverse-Flash, and Thaddeus Thawne, aka Inertia, Bart's Evil Knockoff.
Green Arrow: Along the same line is the otherBadass Normal family - Clan Arrow. Though, it might be better not to ask how many kids Ollie has actually sired.
The Outsiders: A villainous (and obscure) example can be found in the Nuclear Family. They're a group of Ridiculously Human Robots who look and act like a stereotypical '50's sitcom family. Don't let their outwardly affable behavior fool you, though— they're all plenty dangerous, with powers themed after the five stages of a nuclear explosion. Dad can fire massive amounts of radiation, Mom can generate EMPs, Biff can launch thermal pulses, Sis can let out blast waves, and Brat and Dog can transform themselves into fallout.
Shazam!: The Marvel Family -also known as the Shazam Family-: Billy Batson -Captain Marvel-, his sister Mary -Mary Marvel-, his best friend/adoptive brother Fred -Captain Marvel Jr.-, and in the Post-Flashpoint universe, his adoptive siblings Darla, Eugene and Pedro. All of them are Flying Bricks.
Stars and S.T.R.I.P.E.: The comic is about the Courtney Whitmore taking on a superhero identity as the new Star-Spangled Kid in order to annoy her new stepfather Pat Dugan and him returning to superheroics in a suit of powered armor called S.T.R.I.P.E. to protect her, becoming the adult sidekick to a kid hero for the second time.
The Superman Family has the Man of Steel himself, his cousin Supergirl, his alternate reality cousin Power Girl, his half-clone Kon-El, his adoptive son Chris Kent (who was Nightwing for a while), his biological son Jonathan Samuel Kent, his friggin' DOG, Krypto and his cousin's CAT Streaky. They only team-up every so often, but when they do... And if you want to count best friends and family of same, well... look above. And then run.
There is also the multitude of Supergirls: Matrix who Clark considered a sister; Linda Danvers, the Earth born angel who married Pre Crisis Superman and had a child, Ariella, with him; Cir-El who was treated like a daughter by Clark. There's the second Power Girl, Tanya Spears. Family friend, Lana Lang who became Superwoman, and of course Jimmy Olsen, Van-Ze, Ak-Var, and Thara Ak-Var who were all parts of the Nightwing and Flamebird legacy.
In the Superman & Batman: Generations series (as the name implies), Superman, Batman, and several other heroes have children with some intermarrying between the lines. Batman actually acquires immortality and superpowers and marries Superman's great granddaughter (who is centuries old by this point but, like him, ages very slowly after adulthood.)
Brainiac's descendants have all proved to be quite dangerous in their own right. Vril (II) runs a successful police-for-hire company and has managed to defeat Starro two times without much aid, Lyrl usurped said company and almost took over the galaxy as a toddler, and Querl is a superhero and an important member of the Legion of Super-Heroes.
The Royal Family of Paradise Island/Themyscira has this in spades even if the actual members of the family seem to shift and change with every minor retcon to the DCU. Firstly there's Princess Diana aka Wonder Woman, her Retired Badass mother Hippolyta and aunts (usually only Menalippe survives long enough to meet the princess but sometimes three of the four of them are still running around), Hippolyta's sometimes wife Philippus-captain of the guard, Diana's husband the Ace Pilot spy Steve Trevor, Diana's sometimes adopted sister the first Wonder Girl Donna Troy and Diana and Steve's daughter Lyta, the superhero Fury. Diana's other "parent" is generally a Greek god, traditionally Aphrodite but there have also been adaptations that use a quintet of goddesses, Gaia, or Zeus.
The Candy family consists of Boisterous Bruiser Etta, her gun toting protective father Hard, her army officer Thrill Seeker brother Mint, her mother "Sweet", Mint's significant other the bullfighter Pepita and Etta's fiance/husband who varies across continuities but is always a military man with an impressive resume in the main DCU.
The Queens from Arrow. Both Oliver and Thea became superheroes. 100% of your kids becoming professional crimefighters ain't bad. Likewise with the Lances. The father, Quentin, is a police detective and both daughters go on to be masked crimefighters.
The West-Allens from The Flash. Father, Joe, is a police detective, Barry is, of course, The Flash, Iris, is an investigative reporter, and Wally is Kid Flash.
Averted by Slade's wife, Adeline, of all people; in the comics she was a military Action Girl, and the one who trained Slade when he served in the army, before marrying him. In the show, she seems to be just a housewife.
The Batfamily: Batman who is world's best detective and finest Badass Normal who can keep up against metahumans with god-like powers, and his adopted sons: Dick Grayson, former Robin, a Circus Brat who is the brave leader of the eponymous Titans; and Jason Todd, formerly a street kid who vandalized the Batmobile, now-the new more than trigger happy Robin.
Barbara Gordon, who is an Action Girl and a close friend of Batman.
Western Animation
The Royal Flush Gang from Batman Beyond: A family of burglars pulling heists based on playing-cards. .. their daughter's relationship with Terry McGuiness was strangely deja vu.
