Hufflepuff's Founder:
We know it was a House established by one Ms. Helga Hufflepuff. And that its mascot is a badger. So who was Helga Hufflepuff? What does J.K Rowling tell us about her? Since the HP books provide scarce information about its founders, I've had to read between the lines. A lot. That said, I don't think I'm that far off mark regarding Helga's personality. Here's what I know/think about her -
At the outset, we know she was one of the best witches of her time. Though she is more often than not described as 'sweet' and various synonyms of it, she is clearly brilliant enough to hold her own against her peerswho were respectively, people of extraordinary courage, formidable intelligence, and extreme ambition.
She was also homely enough to experiment about the kitchen, and was clearly an accomplished cook whose recipes have continued to be a part of Hogwarts feasts, even a 1000 years later. She was renowned for her cooking charms, so we can safely assume that she was a fairly competent charms user.
She fought fiercely for the right of house-elves, and sought to provide a safe haven for them at Hogwarts. This is clearly a testament to her compassion and sense of justice, but I can't help think she must have been quite unconventional for her age as well. Hermione Granger was considered odd for spearheading the S.P.E.W movement at Hogwarts in the 1990s, at a time when the magical world was seen as having made at least some strides. Now imagine trying something like that a good 1000 years before? It couldn't have been well-received. Even the most well-meaning of wizards and witches must have tried to dissuade Helga from this. However, seeing as the elves have been around since then, I'm guessing Ms. Hufflepuff did not care much about what others thought. She clearly went about doing what she wanted to do and to hell with everyone else! This, I think encapsulates all those qualities the other 3 Founders prized - resilience (she keeps at what she believes in and probably wore others' resistance down, esp Slytherin's I'm guessing) and self-confident (she believed in her mission) and a sort of quiet courage (you HAVE to be brave to go against public opinion!).
Connected to the aforesaid House-elves issue, I'm thinking Hufflepuff might have also had an excellent sense of foresight. Unlike Dobby (who was an exception), most house-elves thrive in an environment where they get to work (without pay) and are appreciated. The ones at Hogwarts do innumerable small and big things to offer comfort to Hogwarts tenants. While having an army of future workers would probably have been the last thing on sweet Helga Hufflepuff's mind, it can't be denied that the house-elves make life at Hogwarts a lot easier for its people. In return, they get sanctuary.
Perhaps the most greatest quality about Helga Hufflepuff is her openness. Her demeanor suggests that she's a charming, cheerful and kind, but unassuming person, who probably cared more about people's personalities than their external appearances. She is also the only one of Hogwarts founders who've refused to accept people on some set criteria. Yes, the Sorting Hat's songs suggest she valued students who were kind, just, fair, hardworking and loyal. But the song also implies that while she valued certain qualities above others, she didn't set them as an elimination criteria. She demonstrated her lack of prejudice by maintaining that she would accept all who wanted to be her students, and would teach each one ALL she knew irrespective of who they were or where they came from.
This isn't really a separate point (could be more of a continuation of Point 4 or even, 5) but I wanted to put this down separately because of I think it deserves a special mention. I think Helga Hufflepuff was perhaps the most mature and perceptive of the 4 Founders. It certainly holds true for her selection of students. In the HP Books, Dumbledore mentions how he thinks students are sorted far too quickly. I believe in that too... Your early years are years when your character forms. Your experiences and your circumstances change your perceptions, and thereby, your personality. Students of other Houses nickname Hufflepuff the 'House of Rejects' mostly because it takes in people the other Houses don't want. Perhaps that's true. May be some students who go to Hufflepuff aren't all that brave or possessing of huge dreams at age 11. May be they are even mediocre in studies. And perhaps, they aren't even all that kind or nice or fair as all Hufflepuffs are meant to be. But so what? That's why you go to school, right? To learn. You can learn team work, fairness and kindness at school as much as you can learn potions, astronomy and transfiguration. Helga Hufflepuff knew this. She knew that mediocre students could succeed through tenacity, that work ethics could become the stone that sharpens their ambitions, and that perhaps, true friendships and loyalties were what were needed for someone to emerge a truly amazing and brave witch or wizard. Most importantly, she knew that most people needed a chance to prove themselves to be more than what others saw them to be. And she gave it to them.
So when you think about it, Ms. Hufflepuff was probably amongst the first feminists of the magical community. She was sweet, giving, fair-minded and kind. She was equally open-minded, brave, determined and unconventional. In other words, Quite Amazing.