Lily and Severus
Re-reading all the books and I just got to Snape's memories in the DH.
I realised while everybody talked about Harry's dad and his qualities, or in Snape's case his misgivings, hardly anyone ever told Harry anything about his mother except that he's got his mum's eyes.
The very first time Harry saw anything at all related to his mother are through Snape's eyes and his memories do show Lily as a likeable person. Snape was clearly besotted with her early on and he regretted her death greatly. But more so, Harry got to see how his mother truly was, her sweetness, kindness, concern for a friend (she asked Severus how are things at home), strong moral compass (she questioned Snape over his friends who later became Death Eaters). I find it bitter sweet that the most Harry knew about his mom was that she was a muggle who gave her life to save him until in those memories he saw so much more and came to finally understand the kind of person she must have been.
While Sirius and Lupin talked about his father's bravery and fun-loving side, popular for being a Seeker and overall well-liked, Snape showed him how caring, kind, and fair his mother was and I find it beautiful.