Jin/Xiaoyu's ending. While Pandora doesn't cure Jin's Devil Gene (it just stops him from going into Pandora mode), Xiaoyu saves him from freezing in the Antarctic and he promises to keep on looking and not giving up.
In a sense, their Trailer reveal with M. Bison and Juri. Juri has Xiaoyu on her back with her foot on the girl's face. And seeing Xiaoyu in trouble is enough to trigger Jin going into his Devil state.
In Guy and Cody's ending, the two reminisce about their past as allies in defending Metro City against Mad Gear. The eternally bored Cody acknowledged their adventure as "definitely not boring", while the perpetually frowning and formal Guy smiles and says in a surprisingly casual tone "That's good to hear, man."
Remarkably enough, Bob and Julia's ending. Julia tries to offer Bob the money she owes him for helping her find Pandora, but he declines taking it, perhaps knowing that it could be put to better use researching Pandora.
Poison and Hugo's ending. Their original plan was to go to Antarctica to get some attention, but find out that there is no media. However, the two realize that they've become better just by fighting everyone else and that nothing could stand in their way, sharing a high-five with each other. The two end up creating their own wrestling association without the influence of the Pandora Box, proving that they can make their own dreams come true.