Urutoraman Gaia

This series is different from other Ultraman sagas in that Gaia is not a space patrol from M78 nebula. Instead Gaia is an embodiment of power of the earth to protect itself from threats from outer space, and from the human race who's on fast track to destroying its own planet.

It's an environmental themed version of Ultraman, and some episodes are related to various environmental destruction of the planet. Ultraman Gaia features another Ultraman named Ultraman Agul who's identity is mysterious and unknown.

The series has very good character development of each of the members of XIG (eXpanded Interceptive Guardians), and contains few humorous scenes about them.

I just love these Heisei Ultraman series (series made after emperor Akihito took reign). They're beautiful, original, and has very good production and stories. Although made for the young set, the series is entertaining to adults as well. This or these are the best science fiction super hero series from Japan, and should be entertaining to wide range of audiences.