Sora is the worst waifu in the multiverse. Don't get me wrong, I like the tomboy thing as much as the next guy, but a tomboy doesn't need to be a huge bitch, which Sora is. At the beginning of Adventure, it's fine, because the point is that they all lost the qualities that they used to embody. Sora needs to relearn how to love. And they say she does that. She then continues to be a stupid emo bitch for the rest of the series and its sequels. She throws a bitchfit at Taichi because he got her a present that wasn't good enough for her. This bitchfit involves ignoring his calls, even though she knows that they're basically on a team of superheroes together, and because of this she refuses to help them try to stop a nuke aimed at their city. Then she goes off to fuck bad boy Yamato instead anyway. Guess that was a really shitty hairclip.
Mimi is the literal embodiment of purity. Best waifu. Hikari is a bit of a mary sue, but she's better than sora, and she has the loli thing going on with a bit of tomboy tinge anyway. Miyako is a bitch but at least they don't pretend she isn't. Ruki and Juri are so much better that I'm pretty sure I don't even need to explain it here. The girls from Frontier and Savers barely have personalities, so at least they don't have awful personalities like Sora. The one from Xros Wars is super devoted, which is a top tier waifu quality. The only worse waifu than Sora is Mei, but we shouldn't even have to count Tri.