I really like 'RWBY in Fairy Tail'. It has great character development as the RWBY girls try to adapt to the Fairy Tail world. Another one is 'Fairy Tail Meets RWBY', which has some exciting battle scenes where characters from both series team up.
One good fanfiction is 'The Magic of RWBY in Fairy Tail'. It does a great job of incorporating RWBY's weapons and fighting styles into the Fairy Tail magic - based world. Also, 'RWBY and Fairy Tail: A New Alliance' is worth checking out. It has an interesting plot that involves a common enemy threatening both universes and how the characters from RWBY and Fairy Tail work together to defeat it. There are some really cool character moments in this one.
There's a fanfic called 'Merging Realms'. In this story, the worlds of Blazblue and Fairy Tail are on the verge of merging. The main characters from both series have to work together to prevent a cataclysm. The fanfic is great because it delves deep into the lore of both franchises, and the character development is really well - done. You can see how the characters grow and change as they face new challenges.
There's also a fanfic called 'Oberon and the Fairy Tail Secret'. In this one, Oberon stumbles upon a long - hidden secret within the Fairy Tail guild. It's full of mystery and action as he tries to figure out what to do with the knowledge he has gained. The author really captures the essence of both Oberon and the Fairy Tail world.
One great Sonya fanfiction could be 'Sonya's New Beginnings in Fairy Tail'. It shows Sonya as she tries to find her place within the guild. She has to overcome her shyness and prove herself to the other members. The story does a wonderful job of character development and also includes some interesting sub - plots with other Fairy Tail characters.
One great Fairy Tail beach fanfiction is 'A Day at the Beach with Team Natsu'. It has all the fun and camaraderie of the Fairy Tail guild members enjoying a day by the sea. There are hilarious antics as Natsu tries to show off his swimming skills, which are not as great as he thinks. Gray keeps freezing parts of the water for fun, and Lucy is just trying to relax and soak up the sun.
One great Pantherlily fanfiction is 'Pantherlily's Adventure'. It shows Pantherlily on a solo mission away from the guild. It's full of action as he battles various foes using his unique abilities. Another is 'Pantherlily and the Lost Artifact' which has an interesting plot where he teams up with some of the other guild members to find a powerful and mysterious artifact.
One great Naruto and Fairy Tail fanfiction is 'Natsu in the Hidden Leaf'. It combines the magic of Fairy Tail with the ninja world of Naruto in an interesting way. The story follows Natsu as he somehow ends up in the Hidden Leaf Village and has to adapt to the new environment while also showing off his Fairy Tail powers.
One great Fairy Tail werewolf fanfiction is 'The Werewolf of Fairy Tail'. It has an interesting plot where a werewolf character joins the Fairy Tail guild and has to deal with the guild's unique dynamics while also hiding his true nature at first. It's full of action and some great character interactions.
One great Sting Fairy Tail fanfiction is 'Sting's Redemption'. It delves into Sting's past and his journey to become a better person. The story has really interesting character development and some great action scenes.
One great 'Fairy Tail Lisanna' fanfiction is 'Lisanna's Return'. It beautifully explores her character after coming back. It shows how she readjusts to the guild and her relationships, especially with Natsu. The story has some really heart - warming moments where Lisanna is shown to be a strong and kind - hearted character again, just like she was before her supposed death.
One great 'Fairy Tail Tartaros' fanfiction is 'Tartaros' Redemption'. It focuses on a Tartaros member who starts to question their evil ways after interacting with Fairy Tail members. It has some really interesting character development and a unique take on the relationship between the two groups.