Atherton and Jack O'Neill could be an interesting pairing. Atherton from Farscape is a complex character, and Jack is a military man with a lot of experience. Their different outlooks could lead to some great banter and conflict. Another could be Chiana and Sam Carter. Chiana is a resourceful and street - smart character, while Sam is a brilliant scientist. They could learn a lot from each other.
John Crichton from Farscape and Jack O'Neill from Stargate. They both have a sense of humor and are great leaders. Jack's military experience combined with Crichton's scientific knowledge would make for an interesting dynamic. They could exchange stories about their different universes and come up with some wild strategies to deal with any threats.
John Sheridan from Babylon 5 and Jack O'Neill from Stargate could make an interesting pairing. Sheridan is a strong leader and diplomat, while O'Neill is a military man with a sense of humor. They could learn a lot from each other. Another could be Delenn from Babylon 5 and Samantha Carter from Stargate. Both are intelligent women with different areas of expertise. Carter in science and technology, and Delenn with her spiritual and political knowledge.
In farscape stargate crossover fanfiction, a fascinating idea is the combination of the different methods of space travel. Farscape has its own style of starship travel and Stargate has the wormhole - based travel. Writers could create stories where characters have to figure out how to use both methods to reach a common goal. Additionally, the clash of different leadership styles from the two shows' characters can add drama. Some characters are more authoritarian while others are more democratic, and seeing how they interact in a crossover situation can be very interesting.
Maybe a character from Stargate, say Daniel Jackson, gets stranded in the Farscape universe. He could use his knowledge of ancient cultures and languages to help the Farscape crew with some of their own mysteries. And in return, the Farscape crew could teach him about their unique technology and ways of survival in a very different and often hostile galaxy.
Ash and Red would be an amazing pairing. Red is such a skilled trainer from the Pokemon adventures, and Ash has his own unique style. They could learn a lot from each other. Red could teach Ash some advanced battle strategies, while Ash could show Red how to be more in tune with his Pokemon's emotions.
The Lone Wanderer and the Courier would be an obvious and great pairing. They both have unique skills and experiences from their respective wastelands. The Lone Wanderer's knowledge of the Capital Wasteland and dealing with the Enclave could be useful to the Courier, while the Courier's familiarity with the Mojave's factions like the NCR and Caesar's Legion could help the Lone Wanderer understand different political landscapes.
Kakyoin and Luffy from One Piece would be an unexpected but fun pairing. Kakyoin's calm and strategic mind would be an interesting contrast to Luffy's carefree and impulsive nature. They could work together in a battle, with Kakyoin using his Hierophant Green to create distractions or attack from a distance while Luffy charges in head - first, using his Gum - Gum powers to take on enemies directly.
In a crossover with 'The O.C.', Ryan and Serena could be an interesting pairing. Ryan's tough - guy exterior and Serena's free - spirit could create a dynamic relationship. Another great pairing could be Blair and Summer in a 'Gossip Girl'/'The O.C.' crossover. Their different styles and personalities would either clash or they could learn from each other. Also, in a crossover with 'Glee', Rachel and Blair could be paired. They both have strong personalities and big dreams in their respective worlds.
Ruby and Joker could be a great pairing. Ruby's enthusiasm and determination combined with Joker's cool - headed leadership skills would make for an interesting dynamic. They could learn from each other's combat styles and ways of thinking.
Xander and Duncan MacLeod could be a great pairing. Duncan has centuries of experience as a Highlander, and Xander has his own unique experiences dealing with vampires and demons. They could learn a lot from each other.