Another interesting one could be 'Harry Potter and Count D: The Forbidden Alliance'. In this story, Harry somehow forms an unexpected alliance with Count D. They might be brought together by a common threat that neither the wizarding world nor Count D's world has faced before. Their combined skills and knowledge from two very different magical backgrounds are used to fight against this new danger.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions from various fandoms, including those that combine 'Harry Potter' and 'Count D'. Just use the search function and type in relevant keywords like 'Harry Potter Count D' to find the ones that interest you.
One great Harry Potter fanfiction is 'The Life and Times' by Jewels5. It delves deep into Lily Potter's life at Hogwarts and her relationship with Severus Snape. It offers a new perspective on the events that led to the Potter family's fate. Another good one is 'Manacled' which has a very interesting take on the post - war wizarding world and Hermione's journey in it. There's also 'After the Battle' which focuses on how the characters heal and move forward after the final battle against Voldemort.
One great D Harry Potter fanfiction is 'The Lightning in the Night'. It offers a unique take on Harry's adventures, with new magical creatures and a deeper exploration of his relationships. Another one could be 'Potter's Parallel Paths' which imagines different scenarios for Harry and his friends. There's also 'Dumbledore's Secrets Unveiled' in fanfiction, which delves into the mysteries surrounding Dumbledore that the original books might not have fully explored.
There are fanfictions where the bond between Harry and Lily is explored through time - travel scenarios. In these stories, Harry might get to meet Lily in her own time and they could form a special connection that helps him understand his family history better. This can lead to some really interesting character development for Harry as he gets to know his mother in a more personal way.
One great fanfiction could be 'Lily's Legacy'. In this story, it explores the bond between Lily and Harry in a really heart - warming way. It might show how Lily's love continues to protect Harry even in different magical situations. Another is 'Harry and Lily's Unseen Moments' which delves into some of the imagined interactions they could have had if Lily had survived. It gives a sense of a mother - son relationship that was cut short in the original series.
I also recommend 'Harry and Fleur: An Unlikely Alliance'. This fanfic starts with a rather forced alliance between them due to some unforeseen circumstances in Hogwarts. As they work together, they discover new sides of each other. It's a long - form fanfiction that really takes its time to build up their relationship.
I've heard of a paraselenic Harry Potter fanfiction that focuses on the Forbidden Forest. The paraselenic influence makes the forest even more mysterious. There are strange lights and new, moon - related magical beings. Harry and his friends have to navigate through this new and dangerous version of the forest, which makes for a really exciting read.
One great 'Ascension' Harry Potter fanfiction could be 'The Ascension of Harry Potter: A New Path'. It often features Harry developing unique powers and taking on a more powerful role in the wizarding world. Another might be 'Ascension's Call' where Harry is guided by an ancient magic towards a greater destiny. There are also some that focus on Harry's ascension in terms of his social standing within Hogwarts, like 'Ascension Among Peers' which shows him rising above the petty rivalries and becoming a true leader.
One good Harry Sirius Potter fanfiction is 'The Bond Beyond Blood'. It explores the unique relationship between Harry and Sirius in a very heart - warming way. It shows how Sirius could have been more involved in Harry's life at Hogwarts if not for certain circumstances.
One popular 'Harry Potter is a redhead' fanfiction might be 'The Red - Haired Harry'. It could explore how his appearance change affects his relationships at Hogwarts. Maybe his friends like Ron and Hermione would react differently at first sight. Another could be 'Red - Headed Potter's Adventures' which might take him on different quests where his new look gives him a unique identity among the wizarding community.