This topic almost seems like it's going in circles.
Anyways, although Avatar isn't "anime", as mentioned by here, I do want to note something of interest. One of the studios that worked on Avatar, Dr. Movie, is actually owned by Madhouse, which is a Japanese animation studio. Alot of work done by Madhouse, they will sometimes give their stuff to Dr. Movie to help lower the work load. However, despite this, Dr. Movie is a very well known studio and their work is probably the highest quality that of a korean animation studio. They tend to produce quality animation.
Admittingly, this is all true, although Transformers is a bit... more complicated. Although the first 3 season of G1 are writen and mainly produced in America, the actual franchies' origin is Japanese and Takara was partially involved with the animated series. The series didn't move to being fully produced by Japan until Headmasters. It wasn't until Transformers Armada and such that the US became involved again with the Japanese studios, although we did have stuff like Beast Wars and the like before this. I should also note that G.I. Joe Sigma 6 is Japanese writen, recorded, and produced similar to Armada and the like. Although, reasons not specified, it has yet to be released in Japan. This could eventually happen sometime down the line.
However, this is getting off topic.