Another possibility is a crossover with 'Danny Phantom'. Danny's ghost powers and the magic of the Fairly OddParents could lead to some epic battles and adventures. They could team up to fight a common enemy, like a powerful ghost who is immune to normal magic but not to Danny's unique ghost - fighting abilities.
One idea could be a crossover with 'The Powerpuff Girls'. The Fairly OddParents' magic could interact with the superpowers of the Powerpuff Girls in really fun ways. For example, Timmy could wish for super strength like Buttercup, but with a magical twist. Maybe his strength would be based on how many good deeds he's done recently.
Well, you could write a 'fairly oddparents fanfiction' where the roles are reversed. For instance, the fairies become the ones in need of help and Timmy has to use his non - magical human skills to save them. Or perhaps a story set in the future where Timmy has grown up and is now a fairy godparent himself, and he has to guide a new, young kid. You could also do a crossover with another kids' show universe, like having some characters from that universe end up in Dimmsdale and interact with the 'fairly oddparents' characters.
Another interesting concept is to write a fanfiction where a new character enters Dimmsdale. This character has a strange connection to the magic of the fairies, and it causes all sorts of chaos and new adventures for Timmy and his friends. Maybe this new character is from a parallel dimension where the rules of magic are different.
Maybe an OC who comes from a long - lost family of fairies. This OC could be on a quest to discover their family's past and their rightful place in the fairy world. They could encounter various characters from the Fairly OddParents universe along the way and have all sorts of adventures with them.
One idea could be a fanfiction where Timmy's new baby sibling gets fairy godparents too. Maybe they have really unique and wacky wishes that cause all sorts of chaos in Dimmsdale. Another idea is a story where a baby from another dimension ends up in Dimmsdale and the Fairly OddParents have to figure out how to send it back while also taking care of it.
One idea could be that Jess from 'New Girl' somehow discovers she has fairy godparents like in 'Fairly OddParents'. Maybe she wishes for a perfect roommate and Timmy's fairies, Cosmo and Wanda, get sent to her by mistake. Then all kinds of wacky adventures start as they try to figure out how to get back to Timmy while also helping Jess with her life in the loft.
The most interesting part is the clash of different power systems. Naruto has his chakra - based ninja skills and the Fairly Oddparents have their magic. When these two collide in a crossover, it creates unique and unexpected scenarios. For example, Naruto might use his shadow clone jutsu while Cosmo and Wanda use their magic to multiply the clones further. It's a wild combination.
One interesting storyline could be Timmy Turner using his fairy godparents' wishes in creative ways to solve problems in the human and fairy world simultaneously. For example, he might wish for a device that can translate all languages so that he can communicate with fairies from different regions and help them resolve misunderstandings. Another could be a story where Vicky, his babysitter, gets a taste of her own medicine through a wish gone wrong and has to experience what it's like to be in Timmy's shoes for a day.
The exploration of new powers and abilities is common too. In a crossover with 'Avatar: The Last Airbender', the fairies' magic could be compared and combined with bending. This allows for new and exciting scenarios where the characters discover how their powers can either complement or conflict with each other.
There's a great 'the fairly oddparents crossover fanfiction' that combines it with 'The Powerpuff Girls'. In this story, the fairies' magic mixes with the superpowers of the Powerpuff Girls. The battles and the way they interact with each other, like Cosmo and Wanda trying to understand Blossom, Bubbles and Buttercup's powers, are really engaging.
Another idea is that there's a mix - up with the magical powers in both worlds. The chakra in Naruto's world and the magic in Fairly OddParents world get intertwined. This causes chaos as ninjas start having magical abilities and the characters in Fairly OddParents start showing ninja - like traits. Naruto and his friends would have to figure out how to separate the two powers again, while also dealing with the mischief that Cosmo and Wanda accidentally create in the process.