02 has Miyako, but like the other two new kids from the beginning of 02, she has two Crests, which kind of muddles things. I end up not convinced that properly represents either Love or Purity by the end of the series. That said, the series doesn't focus on it as much, so the failure here doesn't drag things down as much as with Sora. Miyako is just sort of there, being a bitch for comedy value. Fine. I might argue she ends up being less bad than 02 Hikari since Hikari is just as shallow as she was before, but with that subplot of the Dark Ocean that only tries to add a false sense of depth that doesn't match her character or story at all. Give the Dark Ocean story to Takeru and it would make a bit more sense. It would match up with the darkness that was hinted at when he showed that he still had issues due to watching Angemon die fighting Devimon. But no, they give it to Hikari because she's the most super special thing ever and it's just taken for granted that we love her more than anything, even though she gives us no reason to. She's not even a qt loli anymore.
So then there's Ruki. She pretty much takes what Sora was supposed to do and does it properly, with much more depth since that's the kind of thing Tamers went for as opposed to Adventure, where all the characters represented one emotion. It's not even a contest, really. Of course Ruki has more depth than the previous characters, because her series is more about that. When she plays tsundere, it's much more believable. Especially since she's really only tsundere to Ryu, who would be a bigger Mary Sue than even Hikari if we didn't know what he did in the video games, which Ruki apparently doesn't know. Despite her cold personality, she isn't needlessly bitchy to her friends, at least once she learns that lesson early on. She is cold, but not mean. It gives her personality without going so far as to make her seem like an actual cunt. So yeah, Ruki is way better than Sora, because not only does Tamers deliberately give more depth to the characters, but she essentially fills a similar role to Sora, only she actually does it well.
There's Izumi from Frontier, but who even gives a shit? She's cute and everything, but she's not interesting like Ruki, and she's not the embodiment of Purity like Mimi. Also she is a bitch for no reason to that fat guy who likes her, and it's not like she learns a lesson about that or anything. I know that's supposed to be funny, but I don't find my protagonists being mean for no reason to be funny. I've never gotten this trope.
Also I'll mention Mei from Tri. The biggest Mary Sue since Rey from Star Wars. She makes Hikari look like a real character. Everything revolves around her for no reason, everyone loves her for no reason. The point of the series was nostalgia for the original, so let's have everything revolve around this new girl, even though we're not even including the 02 cast here. She was one of the major things that ruined the series.
Ruki>Mimi>>>Hikari (loli)>Miyako>Hikari (02)>Izumi>Sora>>>>>>>>>Mei