AH! Holy cow I can't believe I forgot about this anime for so long. I used to watch it back when I was first getting into anime (yes instead of the mainstream anime I'd get into obscure random stuff). Anyway the series is called 'Legend of the Condor Hero' and it's based off of one of the most famous Chinese fantasy novel series ever. The series is a must-see for Avatar fans because it contains:
1. A young boy who masters martial arts to save a war-torn world
2. A beautiful mistress who teaches said boy the martial arts and later comes to love him
3. Real Asian culture as opposed to most anime. Also real martial arts... for the most part... sort of
The whole series just has a flavor that reminds me of Avatar (except for slightly older audiences) It has martial arts action (but nothing over-the-top or over-powered), it has non-fanservic-y serious relationships, it has interesting and loveable characters (though really the only two you're going to remember are the main two), and it has just that whole authentic oriental legend flavor that you must be craving. Since Veoh is a site that respects copyright laws I assume it's not bad to post links to it here, so here's a link to the first episodes:http://www.veoh.com/browse/videos/categ ... 77bddjdFWA
For you to get a taste. Normally I'd post a youtube link to the opening or ending theme but this show is so obscure no one on Youtube has posted those kinds of things. Go figure. The subbing group, Live-Evil that did this show is a very good group and they even provide explanatory notes at the end of most episodes. Watch and enjoy!
EDIT: I actually re-watched the first episode myself after making this post for the first time in 4 years, and now I'm starting to realize exactly how much Avatar fans will feel drawn to this series. For crying out loud there's characters that practically scream Azula and Iroh, and the fights will bring back all kinds of nostalgia. Srsly guys, you gotta watch this show.