There's also 'Phantom's Unlimited Potential'. This fanfiction delves into Danny's untapped powers. It shows how he discovers new ways to use his ghost powers, like being able to manipulate time on a small scale within the Ghost Zone. This gives him an edge over other powerful ghosts he encounters.
A really interesting one is 'Danny and the Ghostly Ancients'. Here, Danny teams up with some of the most powerful ghostly ancients. He learns from them and gains their powers through a series of trials. This makes him one of the most powerful beings in the Danny Phantom universe, capable of fending off threats that were previously unbeatable.
One great fanfiction could be 'The Ascension of the Ghost King Danny'. In this, Danny might face new challenges as he fully embraces his role as the Ghost King. It could explore how he manages the Ghost Zone and his relationships with other ghosts in a more regal way.
One popular 'Danny Phantom' fem Danny fanfiction could be 'Feminine Phantom'. It often explores how Danny's character would be different if she were female. It might change the dynamics of her relationships with characters like Sam and Tucker.
One popular 'Danny Phantom Danny Dies' fanfiction might be 'The Aftermath'. In this type of fanfiction, the story often explores how the other characters deal with Danny's death. For example, Sam and Tucker may go through a period of extreme grief and guilt, wondering if they could have done something to prevent it. Another could be 'A World Without Danny', where the entire Amity Park starts to change in unexpected ways due to Danny's absence, showing how much of an impact he had on the town.
One interesting 'Danny Phantom Danny and Ember' fanfiction could be where Danny and Ember team up to fight a new, powerful ghost that threatens both the human world and the Ghost Zone. They start off as reluctant allies but gradually come to respect each other's powers.
In a lot of fanfictions, Danny himself often becomes the most powerful ghost. As he grows and learns to control his powers better, he can surpass many of the traditional powerful ghosts in the show. For example, in some fics, he gains the ability to absorb other ghosts' powers, making him extremely formidable.
There's also 'Box Ghost's Big Day'. This one takes a comical approach, focusing on the often - overlooked Box Ghost. It's full of humorous situations and unique interpretations of the Danny Phantom universe that add a fresh perspective to the story.
One interesting Danny x Dash fanfiction could be 'The Unlikely Bond'. In this story, Danny and Dash are forced to work together on a school project. At first, they clash due to their differences, but as they spend more time together, they start to understand each other better. Danny's secret as Phantom also adds an interesting twist to their relationship.
Some fanfictions might focus on Danny's role in the afterlife as a protector. He could be protecting other spirits or even trying to protect the living from a greater threat that exists in the ghost world. There could also be a theme of identity. Danny has to re - evaluate who he is now that he's dead. Is he still the same Danny, or has death changed him fundamentally? This exploration of self can make for really interesting stories.
One interesting fanfiction could be where Danny's class accidentally gets transported to the Ghost Zone. They have to rely on Danny's ghost powers to survive and find their way back. Another could be a story where a new student in Danny's class has a secret connection to the Ghost Zone and they team up with Danny to face a new threat from there.
You can try looking on fanfiction.net. There are often some great stories there about Danny's class and the Ghost Zone. One I remember has Danny's class getting trapped in a mini - Ghost Zone inside the school. It was really exciting as they had to figure out how to escape while also dealing with mini - ghosts.