Environmental protection is a very common theme, just like in the original series. Fanfic often shows the Planeteers dealing with new environmental threats.
There could be popular ones that have gained a following among fans who are interested in exploring different relationships within the Captain Planet universe. These might be shared through fanfic websites or forums dedicated to the show. But it's hard to determine which ones are the most popular without really diving deep into those communities.
Well, first, make sure you have a basic understanding of the Captain Planet universe. This includes knowing the characters, their powers, and the overall theme of environmental protection. When reading fanfiction, look for unique takes on the characters. Maybe there's a story where Wheeler has to use his power in a completely different way. Also, don't be afraid to leave comments for the authors if you like their work or have suggestions.
There could be a fanfiction where the Captain Planet characters travel to different planets to learn about their environmental conservation methods. For example, they visit a planet where the inhabitants have a unique way of recycling energy that the Planeteers could bring back to Earth to help solve their own energy problems. This would involve a lot of adventure and discovery as they interact with alien species.
There might be a fanfic where the focus is on a different kind of 'power' that comes from their gay relationship. Maybe their love gives them an extra boost in their fight against pollution and evil forces. It could also delve into how they discover and accept their feelings in a world that might not be entirely accepting at first.