The Peverell Brothers:
I mean come on, being the creators of the incredibly powerful magical items of the Deathly Hollows is nothing to slouch about.
The Potter Family:
Harry Potter with his vast accomplishments and chosen one status alone made Potter's one of the most accomplished magical families out there who will go down in history forevermore.
However, even prior to Harry the Potter's themselves were already a very accomplished family, despite not being at the forefront of the magical community quit yet.
Winfred of Stinchcombe Harry’s distant ancestor (also known as the Potterer) for example, was a renowned pioneer who invented many medical Potions during the 12th century, which are still used today in the Wizarding World and who laid the foundation of the Potter family fortune.
Ralston Potter was a member of the Wizengamot from 1612 to 1652. He was a staunch advocate of the International Statute of Wizarding Secrecy International Statute of WizardingSecrecy, in contrast to his more militant peers, who wished to declare war against Muggles.
Abraham Potter another distant ancestor of Harry Potter, was one of the original twelve Aurors of the United States of America.
Henry Potter (Harry’s great-grandfather and namesake) was a wealthy and influential wizard who served on the Wizengamot from 1913 to 1921, he also was very outspoken for Muggle rights, which was one of the chief reasons why the Potter family were excluded from the sacred twenty-eight.
Fleamont Potter (Harry’s grandfather), was a very accomplished potioneer and clever entrepreneur who invented a very successful magical beauty product, which made the already rather wealthy Potter family even wealthier.
James Potter (Harry’s father) despite his premature death was nevertheless known to have been a very accomplished young wizard, who became a full-fleshed Animagi at the mere age of 15 years, he was also a co-creator of the Marauders Map and along with his young wife Lily Potter (née Evans) fought for the Order of the Phoenix during the First Wizarding War, in which they both managed to defy Voldemort himself no less than three times.
The Weasley Family:
Pretty much all of the Weasley children became very accomplished wizards and witches in their own right, with their father Arthur Weasley becoming the head of the Office for the Detection and Confiscation of Counterfeit Defensive Spells and Protective Objects in 1996.
Bill Weasley, who’s the oldest of the Weasley siblings works for Gringotts Wizarding Bank as a Curse-Breaker, he was stationed in Egypt for a time for his work but came back to England to join the Order of the Phoenix during the Second Wizarding War.
Charlie Weasley, who’s the second son of Arthur and Molly Weasley, went on to study dragons in Romania, he was also a very talented Quidditch player and Captain of his team during his school years, he as well joined the Order of the Phoenix during the Second Wizarding War.
Percy Weasley was a very ambitious young man who worked as a personal assistant for Barty Crouch Sr. and at one point as the Junior assistant for the Minister of Magic, he went on to become the Head of the Department of magical transportation sometime after the war.
Fred & George Weasley were very clever inventors and went on to become very successful entrepreneurs after leaving school and fulfilled their dream in opening their own joke shop in Diagon Alley, known as “Weasleys' Wizard Wheezes”, with a bit of financial help from Harry Potter. Both brothers also joined the Order of the Phoenix and respectfully fought in the battle of Hogwarts at which Fred Weasley tragically lost his life.
Ron Weasley alongside his best friend Harry Potter holds a Special Award for Services to the School to his name, for his work concerning in resealing the Chamber of Secrets. He along with the rest of the trio also received his own chocolate frog card for his accomplishments in helping to bring down Lord Voldemort. After the war, Ron went on to become one of the youngest Aurors in magical history and alongside Harry revolutionized the Auror department and helped ”make a new world” for the wizarding community.
Ginny Weasley, was a very charming and talented young witch and Quidditch player, who went on to play professionally for the Hollyhead Harpies after finishing school, she also was a member of the DA and fought alongside her family and soon to be husband Harry Potter during the Battle of Hogwarts.