I am a member of MANY different fandoms, especially when it comes to fanfics.

My favorites are (along with the type of story)

Any reading/watching the books/series/movies fics

Percy Jackson: Mist disappears, meeting Percabeth, going to Hogwarts (especially where Percy is Voldy's grandson), Percy joins a crossover team (like Avengers, Justice League, or Young Justice), genderbent Percabeth

Harry Potter: Gryffindor Draco, time travel to different generations, dead come back to life

Spider-Man: identity reveal, Syperfamily, kidnappings/torture turned fluffy

Alex Rider:secret gets out, K-Unit team bonding, kidnapped by SCORPIA and K-Unit rescues him, femAlex/Eagle

Danny Phantom: identity reveal, going into Danny's mind, Danny/Dani father/daughter, going into the ghost zone, snarky/savage Danny, extremely codependent trio (especially Strength by WildBurnsTheForest on fanfiction.net), and genderbemt trio (femDanny maleSam eitherTucker)

One Piece: strawhats watch Luffy memories, ASL with the Whitebeards, ASL as a crew, escaped slave Luffy AUs, time travel to pre 2 year break, femLuffy, different devil fruit Luffy

HTTYD: Hiccup runs away before final test (either to a dragon rider city, to make his own tribe of riders, or just to live amongst dragons), kidnapped by any enemies, crossovers with other Big Fours

Rise of the Guardians: watch Jack's human memories, real world AUs, Jack's staff is broken, sick fics, crossovers with other Big Fours

Big Four: going to Hogwarts (Gryffindor Merida, Ravenclaw Rapunzel, Hufflepuff Hiccup, and Slytherin Jack), real world AUs, seasonal spirits

Star Wars Rebels(pre season 3. Not a fan after that all that much): the crew learns more about Ezra's street life, Ezra kidnapped by Inquisitors, and I found one where the crew was frozen in carbonite, and they don't get out until Ezra is like 22 with his own padawan