Well, 'Hermione's Secret Power' is an interesting fanfiction. In this story, Hermione discovers a power she never knew she had and has to learn to control it while still being true to herself. It's full of action and her character is written very true to the original. There's also 'Hermione in the Muggle World' which is a unique take. It shows Hermione trying to navigate the Muggle world with her magical knowledge and how she copes with the differences, making for a really engaging read.
Well, a really interesting plot twist could be Hermione's role in the Slytherin house. She could become a leader, using her intelligence to reform the house's more negative aspects. Or, she might be caught in the middle of a power struggle between different Slytherin factions. Also, her interactions with the Slytherin pure - blood families could be full of drama. Maybe she discovers a family secret that could change the whole wizarding world.
One cool plot twist is when Hermione discovers that Edward has a hidden power that is related to her magic. Maybe he can absorb and use some of her magic energy, which leads to a whole new set of challenges and adventures as they try to understand and control this new aspect of their connection.
In some fanfictions, the plot twist is that Hermione's magic has a different effect in Middle - earth than it does in the Harry Potter world. For instance, her spells might accidentally cause a rift between different races in Middle - earth, and she has to find a way to fix it while also dealing with the main quest of the dwarves to reclaim Erebor. It adds a whole new layer of complexity to the story.
One interesting plot could be that Hermione discovers she is related to Voldemort in a prophecy. This prophecy states that she has the power to either destroy him or become his most powerful ally. She then has to make a choice, and the fanfic could explore her internal struggle as she decides which path to take.
You can find a lot of interesting Hermione fanfiction on websites like Fanfiction.net. It has a huge collection of fan - made stories about Hermione and many other Harry Potter characters. Another good place is Archive of Our Own (AO3). It has a great tagging system, so you can easily search for Hermione - centric fanfictions and sort them by popularity, kudos, etc.
A plot where they are forced to team up to solve a mystery within Hogwarts. It could be a mystery related to the Chamber of Secrets or some other hidden part of the castle. During this time, they have to rely on each other's strengths, and Hermione starts to see Snape as an ally rather than just a strict teacher.
One interesting plot is when the Great Hall is turned into a magical maze for a special event. Harry and Hermione have to work together to get through it. Along the way, they face different magical creatures and challenges, and it really tests their friendship and magical skills.
I think Dolohov could be the most interesting. He's a Death Eater, so he has a dark and mysterious side. Meeting Hermione could be a turning point for him. His interactions with her might make him question his loyalty to Voldemort. It would be fascinating to see his internal struggle as he deals with Hermione's goodness and intelligence.
A really interesting plot twist could be that Snape was under a spell all along that made him seem so cold and distant, and Hermione discovers it. This changes the whole dynamic between them. Another twist could be that Hermione is actually related to someone from Snape's past in a way that they never expected, which brings them closer.