Luna Lovegood

Although she was odd, she helped Harry find the lost diadiem, she joins Dumbledore’s Army and she always stood with her friends. Ginny and Harry even named their daughter and third child, Lily Luna Potter, after her. 

Professor Remus Lupin

He was alive, he was always looking out for Harry. Not only did Lupin teach Harry how to to defend himself from Dementors, he was also the best Defense Against the Arts teacher ever. Plus, he walked around with pockets full of chocolate.

Colin Creevy
After being Petrified, sympathyfor Colin grew. By the end of the saga, Colin (who was Muggle born) showed his true Gryffindor bravery by staying at the Battle of Hogwarts even though he was underage. He lost his life because of that choice.

Dean Thomas
He grew up believing that he was Muggle born. Because he couldn’t prove his wizard pedigree, he had to go on the run at age 17 so that he wouldn’t be thrown into Azkaban. He was also a member of the Dumbledore’s Army and he was always supportive of Harry when hardly anyone else believed in him.

Molly Weasley

She's not that underrated or obscure but she is the real parent figure in Harry’s life it’s Molly herself. She sends him a Christmas present before she’s even really met him, and from the moment he steps foot in the Burrow, it’s more of a home than anywhere outside Hogwarts. she has no connection to his parents, doesn’t know about the prophecy, didn’t fight in the first war: she simply sees a child without a mother and her first impulse is to gather him into her brood. 

Percy Weasley 

Despite his annoyingly stubborn loyalty to following the rules and having a career in the Ministry, Percy did help protect Harry and the other students during various Hogwarts calamities. He also looked out for his younger siblings, whether they wanted him to or not, which showed he had their best interests at heart.

Aberforth Dumbledore
Aberforth was instrumental in assisting Harry, Ron, and Hermione during their hunt for Voldemort’s Horcruxes, saving them from Death Eaters on more than one occasion and allowing his pub to act as a thoroughfare in and out of Hogwarts. He was also an original Order of the Phoenix member and fought during the Battle of Hogwarts.