Lucario could be an amazing addition. As a Pokemon that can sense auras, it could have a unique connection to the Force. In a Star Wars setting, it could be a protector of a hidden Jedi temple or a guide for a lost Padawan. Its combat skills and ability to sense danger would make it a valuable asset in the dangerous Star Wars universe.
Charizard would also be great. It's a large, dragon - like Pokemon that could fit well into the Star Wars aesthetic. It could be a wild Pokemon that a group of rebels or stormtroopers encounter on an unexplored planet. It could either befriend them or become a formidable enemy depending on how they interact with it.
Definitely Ash Ketchum. He has so much experience with Pokemon and would be really out of place but also very interesting in the Star Wars universe. He could learn about the Force and maybe use it to communicate better with his Pokemon.
Definitely Luke Skywalker. He could bring his Jedi wisdom to Earth and teach people about the Force. Han Solo would also be great. His roguish charm would be fun to see on Earth. And of course, Darth Vader. His imposing presence would create a lot of drama.
Han Solo and a Skaven from Warhammer. Han's roguish charm and ability to get out of tough situations could be pitted against the devious and sneaky Skaven. The Skaven's underhanded tactics and Han's quick thinking would make for some really entertaining encounters as Han tries to outwit the Skaven in various situations across the two universes.
I think Dom Santiago from Gears of War and Han Solo from Star Wars would be interesting. Dom's loyalty and Han's roguish charm could lead to some really fun and unexpected interactions. They could be on a mission together, with Dom's military skills and Han's piloting abilities complementing each other.
Definitely Darth Vader and Jack O'Neill. Darth Vader with his imposing presence and dark side powers would be a formidable force against the Stargate team. Jack O'Neill, with his military experience and sense of humor, would be a great contrast. Their interactions could be really intense and full of conflict.
Definitely Indiana Jones and Han Solo. Indiana's tenacity and knowledge of archaeology combined with Han's roguish charm and piloting skills would make for some great interactions. They could be on a quest for a valuable artifact that has significance in both the Star Wars galaxy and on Earth.
Definitely the Lotus from Warframe. She could be like a wise advisor to the Jedi Council, sharing her knowledge of the Orokin and the Tenno. And Darth Vader would be a great addition too. Imagine the confrontation between him and a powerful Warframe like Excalibur. It would be an epic battle of light and dark powers.
Ash Ketchum would be a must - include. Imagine him using his knowledge of Pokemon to master Beyblade battles. Also, Gary Oak could be his rival in this new form of combat. From the Beyblade side, Tyson could be an interesting addition. He could bring his Beyblade skills and learn about Pokemon. And of course, Pikachu as a character - like presence in the form of a Pikachu - themed Beyblade would be really cool.
Definitely Ben Tennyson himself. His ability to transform into various aliens would add a whole new dynamic to the Star Wars universe. Also, characters like Darth Vader would be great. Imagine the confrontation between Ben in one of his powerful alien forms and Vader with his lightsaber and the Force. Another interesting character could be Yoda. Yoda's wisdom and his unique view of the Force could interact in an interesting way with Ben's more action - based alien powers.
Kakashi would be an interesting character too. His calm and collected nature, along with his vast knowledge of jutsu and combat, could make him a valuable asset in the Star Wars world. He might be like a wise old Jedi master, teaching younglings about both the ways of the Force and the ninja arts.