I'd recommend starting with the most popular ones on websites like Archive of Our Own. They usually have a good summary that can give you an idea if it's the type of story you'll like.
One great Spider - Man and She - Hulk fanfiction is 'The Team - Up'. It has an interesting plot where they have to solve a mystery in New York City together. The way the author writes their interactions is really engaging.
I'm not sure who the absolute best is, but there are some well - known writers in the fanfiction community. Some writers who have a great understanding of both characters' personalities and powers tend to write really engaging stories. You can often find them by looking at the reviews and ratings on fanfiction websites.
She fits in by bringing her unique skills. Her acrobatic abilities and spider - sense are assets. For instance, in a story, she could be the key to detecting an enemy's ambush before the Avengers walk into it.
The plot could involve She - Venom being an outcast in the symbiote world and Spider - Man being the only one who tries to understand her. The 'lemon' aspect might be a slow - burn romance where they gradually fall for each other. They could start with simple acts of kindness towards each other, like Spider - Man saving She - Venom from a mob of angry citizens who mistake her for a villain. As time passes, they become closer and closer until they share a passionate kiss.
The Kingpin could be a great antagonist. He's always been a thorn in Spider - Man's side, and his criminal empire and resources would pose a major threat to both Spider - Man and She - Hulk. He could hire super - powered mercenaries to fight them.
One storyline could be Spider - Man and She - Hulk teaming up to stop a powerful villain who is stealing experimental technology from Oscorp. Spider - Man uses his agility and web - slinging skills while She - Hulk uses her super strength. Another could be a story where they get transported to an alternate dimension and have to find their way back home while facing strange new enemies. Maybe they also have to deal with a misunderstanding between them at first, like Spider - Man thinking She - Hulk is too reckless, but then they learn to work together effectively.
One great crossover could be a story where She - Hulk and Spider - Man team up to take on a powerful new villain in New York City. Maybe a villain with the ability to manipulate technology and they have to use their combined strength and agility to stop him. Another could be a more comical crossover where Spider - Man accidentally swings into She - Hulk during one of her law - related outings, leading to some chaotic and funny misunderstandings as they figure out how to work together.
One great storyline could be She - Hulk and Spider - Man teaming up to take on a powerful new villain in New York City. Maybe a villain who has the ability to manipulate the legal system and is causing chaos for She - Hulk in her day job as a lawyer, while also creating dangerous situations for Spider - Man on the streets. They have to combine their skills, with She - Hulk using her legal knowledge and brute strength, and Spider - Man his agility and web - slinging skills to bring the villain to justice.
Another aspect is the potential for new character dynamics. She - Venom can bring a whole new set of emotions and reactions to Spider - Man. They might have a more complex relationship, not just as allies or enemies but something in between. Like in some fanfictions where She - Venom has a grudging respect for Spider - Man that slowly turns into a deeper bond over time.