I am a Michelle Kwan fan and a Yu-Na fan. In a way I think it's quite fitting that these two skaters--one of whom influenced the other in skating philosophy and in emphasizing artistry--never met in competition. They both missed the 2006 Olympics for different reasons--Michelle because of her re-injury and Yu-Na because of the age restriction.
Though the Yu-Na fan in me cringes when folks say Yu-na is nothing but 3/3s (...really?) and the Michelle fan in me cringes when people criticise Michelle's technical content (given that she grew up under 6.0 where she didn't have to do CoP level elements), I do find parts of this discussion fascinating as well as frustrating.
I would even go as far to say that in terms of consistency and skaing clean - Yuna is closer to Sasha than she is to Kwan...

Okay, I find this really perplexing given the huge disparity in results between the two (and if medals don't matter what separates Sasha from Michelle?). Yu-Na was far more consistent than Sasha and far cleaner when it mattered most.
For the past 10 years, every ladies worlds champion but two have not been able to medal the year after they won worlds. The two exceptions? Michelle Kwan and Yu-Na Kim. Every other either failed to podium or for unrelated reasons were unable to defend their title (Irina, for health reasons in 03 and for not deciding to compete in 06). Yu-Na has definitely had less overall success at Worlds than Michelle, but medaling all four years at Worlds inlcuding 1 title is more than impressive considering she's the only one to have done that in that timeframe. So there's one proof of consistency that makes Yu-Na more similar to Michelle than Sasha (who only had 3 world medals, no world title, no OGM, etc).
Then there's that little matter of the importance of the OGM. Does one
need an OGM to be great? Not in my opinion, and I fully agree that Michelle is great. But it confuses me when people appear to discount an OGM completely, presumably because Michelle did not win it. The train of thinking apparently went from, "It doesn't matter that Michelle didn't win the OGM" to "It doesn't matter when anyone wins an OGM."
IMO, I believe Yuna and Sasha have more in common than say Yuna & Kwan or Yuna & Irina. Totally different eras, totally different set of rules. And with all due respect to Yuna, she simply doesn't have the resume of these two - their greatness is based on longevity, impact and legendary status.
Is Michelle a legend in Russia and is Irina a legend in the USA? I think legendary status may be in the eye of the home country. Michelle is an American icon but I'm sure Russia, while respecting Michelle, thinks of Irina as legendary. And vice versa. Yu-Na is most definitely a legend in Korea already.
As for longevity, no one can match the longevity of Michelle or Irina simply because the rules lock skaters out now at an earlier age when those two were competing on the senior level already. It's quite exceptional and wonderful that they skated as long as they did but I don't think that gives the two (both of whom i greatly respect) a monopoly on greatness. Yu-na accomplished a great deal internationally in her 2 years as a junior, it's a pity that many never got to see it.
Actually, 8 years after Sarah Hughes' win in SLC, the New York Times was still lavishing praise on her for her Olympic performances. Sometimes you don't need years to be remembered, you just need 8 minutes. I believe Yu-na will remembered by more than just the people in her country, given the astounding amount of end of 2010 mentions her Olympic performances received by press outside of Korea.