Another interesting concept is a character - based crossover. A Joe like Snake Eyes could form an unlikely bond with a Transformer like Bumblebee. Snake Eyes' ninja skills could be used in combination with Bumblebee's speed and agility in combat. They might start off not trusting each other but gradually learn to work together as they face various threats.
The key is to find common ground. Both have their own groups of heroes and villains. You can start by having a threat that affects both universes. For instance, a new evil force that wants to take over both Earth (where the Joes operate) and Cybertron (the Transformers' home). This forces the two groups to collaborate.
One common theme is the idea of unity. Different groups, like GI Joe and other fictional teams, come together to fight against Cobra. This shows how cooperation can overcome a powerful threat.
One idea could be to have Snake Eyes cross over into a modern urban setting where he has to use his ninja skills to fight a new kind of crime syndicate. Maybe he teams up with a local detective who is initially skeptical of his methods.
The Spartans' superhuman strength and advanced armor could be combined with GI Joe's stealth and infiltration skills. For example, a Spartan could provide cover fire while a GI Joe operative sneaks in to disable an enemy base's defenses.
Maybe a character from Halo, like Master Chief, gets transported into the GI Joe universe. He has to adapt to their different warfare style and politics. Meanwhile, the GI Joe characters are in awe of his advanced armor and combat abilities. This creates a lot of interesting interactions as they try to figure out how to send him back while also using his skills to fight their own enemies.
Cobra Commander could also be a great addition. His evil plans and his forces could provide the main conflict for Snake Eyes in the crossover. And if we want to expand the scope, characters from other military - themed franchises could be included. For instance, characters from 'The A - Team' could make for an interesting crossover. They have different fighting styles and personalities that could clash or mesh well with Snake Eyes. Imagine Face and Hannibal devising plans while Snake Eyes executes them with his ninja stealth.
One popular 'gi joe rise of cobra crossover fanfiction' is 'The Joes and the Autobots' which combines the GI Joe universe with the Transformers. It has an exciting plot where the two teams join forces against a common enemy.
Some of the valuable GI Joe comics include rare first editions and limited print runs. Also, comics featuring significant storylines or popular characters tend to hold higher value.
I'd suggest 'GI Joe: Snake Eyes' if you're into the character. It offers a deeper dive into his background and adventures. Also, 'GI Joe: Special Missions' is worth checking out for its diverse and action-packed missions.