Edward and Phoebe would be a fascinating pair. Edward's mind - reading ability and Phoebe's premonition power could lead to some intense and interesting interactions. They could also use their powers together to predict and prevent disasters in the crossover world.
Buffy and Carlisle would be an interesting pairing. Carlisle's calm and ethical approach to vampirism could contrast with Buffy's more action - oriented slaying. They could have deep discussions about the nature of good and evil in their respective worlds. Another interesting pair could be Willow and Alice. Willow's magic and Alice's precognition could lead to some really cool interactions and joint efforts to foresee and prevent threats.
I think Buffy and Edward would be a really interesting pairing. Buffy is used to dealing with vampires that are evil, and Edward is a 'good' vampire. Their interactions would be full of tension. Buffy might be skeptical of Edward at first, thinking he's hiding something more sinister. And Edward would be fascinated by Buffy's strength and courage, but also a bit intimidated by her no - nonsense attitude.
Eric Northman and Edward Cullen would be an interesting pairing. Eric is a bold and often ruthless vampire in True Blood, while Edward is more brooding and conflicted in Twilight. Their different personalities would create a lot of tension.
Another great pairing could be Jacob and Grover. Jacob is a werewolf with a strong sense of loyalty and Grover is a satyr, always looking out for demigods. They both have a connection to nature in different ways. Jacob with his wolf form and Grover with his love for the wild. They could have some really fun adventures together as they explore both the Twilight and Percy Jackson worlds.
One interesting pairing could be Edward and Deadshot. Edward's ability to read minds could be really useful in helping Deadshot with his aiming. Deadshot, on the other hand, could teach Edward about human combat techniques that the vampires might not be familiar with.
Well, for me, Angel from 'Maximum Ride' and Alice from 'Twilight' would make a great pairing. Angel's psychic abilities and Alice's ability to see the future could lead to some really interesting interactions. They could work together to predict and prevent disasters in the crossover world. Also, Iggy from 'Maximum Ride' and Jasper from 'Twilight' could be an unexpected but cool pairing. Iggy's blindness and his other heightened senses might intrigue Jasper, who has his own unique vampiric abilities.
Ron Swanson and Jacob Black. Ron is all about his manly ways and love for meat and simplicity. Jacob, as a werewolf, also has a sense of masculinity. They could have a competition over who is more manly. Maybe they start a wood - working project together, but Ron is constantly annoyed by Jacob's werewolf - related absences when the moon is full.
One interesting pairing could be Edward and Kendall. Edward with his brooding, mysterious nature and Kendall, the confident leader of Big Time Rush. They could have some really cool exchanges, like Edward trying to understand Kendall's passion for music while Kendall is intrigued by Edward's vampire abilities.
Yukari (from Persona 3) and Chie (from Persona 4). Yukari is very outspoken and has a bit of a sarcastic side, while Chie is energetic and a bit of a tomboy. Their different personalities could lead to some really fun and comical interactions, especially when they're facing Shadows together or just hanging out in the school setting.