One of the best is 'The Alien Costume' saga. It introduced Venom in a very impactful way. The concept of the symbiote attaching to Spider - Man and then later to Eddie Brock was really cool. It explored Spider - Man's struggle with the new powers and the darker side of the symbiote. It also set up the long - running feud between Spiderman and Venom.
The Spiderman vs Superman 1978 comic is quite rare. It was published during a specific time and had a relatively small print run, making it hard to come by these days.
Perhaps there is a powerful artifact that both Spiderman and the Avengers are after. They end up in a conflict over it. Spiderman, with his street - smart ways, tries to outwit the Avengers and get the artifact for himself, believing he can use it for good in his own way.
Definitely 'The Alien Costume' arc. It's a classic. It was a huge turning point in Spider - Man's story, introducing the symbiote which would later become Venom. The whole idea of the black suit changing Spider - Man's personality a bit was fascinating. And when it finally turned into Venom, it created a powerful and memorable villain for Spider - Man to face.
Perhaps there's a power - stealing device in the fanfiction. It's stolen by a villain and used on the Avengers, but Gwen is immune. So the Avengers, now with reduced powers, end up fighting Gwen who is trying to get the device back. Or it could be that Gwen discovers a threat to her world that the Avengers don't believe in, and they try to stop her from taking action, leading to a conflict.
However, if the fight is in a more enclosed space, like an old warehouse, Batman's stealth and combat skills could give him the upper hand. He's trained in multiple forms of martial arts and is a master of using the environment to his advantage. But Spiderman's spider - sense could also be a game - changer, warning him of Batman's attacks even in the dark. So, it's hard to say for sure who would win.