There are fanfictions that rewrite the Dursleys' characters completely. In one, the Dursleys are actually secretly working for a good cause in the wizarding world but have to pretend to be horrible to Harry to keep their cover. In another, they are under a spell that makes them act the way they do towards Harry, and when the spell is broken, they become loving and caring relatives. Also, there could be a fanfiction where the Dursleys are part of a prophecy themselves, and their actions towards Harry are all part of a grander plan in the wizarding universe.
One popular fanfiction might be about the Dursleys' secret past that somehow ties them to the wizarding world in a more complex way. For example, perhaps there was a wizard in their family line long ago that they've been trying to hide. Another could be a story where the Dursleys have a change of heart much earlier than in the original series and start to embrace Harry's magical nature, leading to all sorts of comical and heartwarming situations as they try to understand the wizarding world. And there could be a fanfiction where the Dursleys are forced to face the consequences of their mistreatment of Harry in a more magical and extreme way, like being haunted by magical apparitions that represent Harry's pain.
One interesting fanfiction could be about the Dursleys having a change of heart before Harry goes to Hogwarts. Maybe they start to see the magic in him in a different way and struggle with their newfound feelings of protectiveness. It could show a different side of the usually cruel Dursleys.
One interesting Dursleys fanfiction could be about Dudley's life after learning the truth about the wizarding world. Maybe he starts to have a change of heart and tries to make amends for how he treated Harry over the years.
There might be a fanfiction where the Dursleys are actually related to a minor wizarding family in some convoluted way. This discovery could lead to a whole new set of adventures and relationships for them. They could be dragged into a wizarding mystery that forces them to cooperate with Harry and other wizards, which would be a huge change from their usual behavior of trying to avoid all things magical.
Yes, there are. Some fanfictions focus on the Dursleys' hidden depths. For example, in certain stories, Petunia's jealousy of Lily is explored in a more complex way, showing how her upbringing and the magical world's intrusion into her normal life affected her actions towards Harry. These fanfictions often give the Dursleys more humanizing qualities, like Vernon's insecurities about his normalcy compared to the magical world, which is a fresh perspective compared to their rather one - dimensional portrayal in the original books.
In some fanfictions, the Dursleys might be portrayed as having a change of heart. For example, they could start to secretly admire Harry's magical abilities instead of resenting them. This can add an interesting twist to the original story.
One interesting fanfic could be where the Dursleys are secretly magical but have been suppressing it. Maybe in this fanfic, Vernon Dursley has a hidden ability to communicate with magical animals, which he has always feared and tried to hide. This would completely change the dynamic of how they treat Harry as they are also hiding their own secrets.
One prank could be Harry using magic to make all of Dudley's clothes two sizes too small overnight. Another might be making the Dursleys' living room furniture float whenever they try to sit down. And he could also use magic to make the food on their table turn into slugs when they're about to eat.
A great 'Harry Potter Dursleys fanfic' might explore the Dursleys' backstory more deeply. For example, it could show how Vernon's hatred for magic and strange things developed over time. Or it could focus on Petunia's envy of Lily's magical abilities and how that affected her relationship with Harry. Some fanfics also imagine a scenario where the Dursleys are magically transported to Hogwarts and have to adapt to the magical environment. They would be completely out of their element, and it would be interesting to see how they interact with the students and teachers.
They are popular because the Dursleys are such complex and disliked characters in the original series. Fanfictions give readers a chance to explore their motives and potentially redeem them. For example, we can understand why they treated Harry so badly in some fanfictions which might be due to their fear of the unknown world of magic.
One great fanfiction could be where Harry and Neville team up to discover a hidden magic within Hogwarts. They might find a secret chamber that holds ancient spells and have to work together to unlock its mysteries. This could show their different strengths - Harry's courage and Neville's knowledge of plants and Herbology coming together in an exciting adventure.