Definently Korean. Korean has emotions, graceful instruments, and I can feel Princess Serenity's romance.
As for Japanese, I never enjoyed Dali's version, but Moon Lips was the best one. I can feel how epic and strong the senshi can be. Plus, it was tracked during S and Super S, my favorite seasons!
Also, Cantonese was cool. Instruments were awesome, and most of all, calm and dreamy the singer is.
From a passing view of only the first video (second one was blocked for me too, and I'm not sure how to use a proxy), I would say Malay and Korean stand out as really good. (I remember a good Cantonese version of Sailor Star Song, too...)
I will say, even though Germany didn't use Moonlight Densetsu and instead elected to make totally new songs, I really like Sag Das Zauberwort too (and the Dutch version of that as well).
In the Snow White Casting Episode (the one with Mikan Shiratori, not the episode in R Season), Naru & Usagi were allowed to torture our ears with German lyrics (totally unrelated to the original, though).