As the list Anime News Network had didn't have #47 and the TV Asahi page is no longer there, I found a full version of the list here. And that says The Twelve Kingdoms was number 47.
It's a recent series, starting in 2002 and based on a series of fantasy novels that began in 1992. And it's been release in English by Media Blasters in the US and Madman in Austrailia. And Tokyopop are due to release the novels starting in 2007.
I think I ignored it on release due to the fact it's about a Japanese girl who is transported to a fantasy world and I think I'd had my fill of stories about Japanese girls transported to fantasy worlds by that point.
My understanding of it's status in the west is that it's relatively unwatched, but acclaimed by those who have seen it. It's a long series (45 episodes/10 DVDs) and even shopping around it's still going to set you back about £80 to pick up the entire show, which as I've said many times before, is too expensive for a TV show.