I have to respectfully disagree with Mac on the Heisei Ultraman series, TIGA, DYNA and GAIA. Granted, TIGA was the first domestic Ultraman produced half-hour series since ULTRAMAN 80, and so it takes a while for them to find their footing in terms of integrating CGI and digital mattes, but that all sorts itself out by the middle of the series. TIGA was so popular, that it relaunched the franchise which had essentially been floundering for 15 years.
While ULTRAMAN DYNA adds a little more humor to the mix, it is one of my favorites for a number of reasons, including the characters and the designs, and ULTRAMAN GAIA is the first to contain multiple series-long story arcs, that come together in the finale with Earth Monsters and Ultraman fighting the ultimate evil. In these three series there are some great, great episodes, characters, and a lot of memorable monsters; therefore I would dismiss it so offhandedly. I would say check them out for yourself, before judging them — the same with the series I will comment on in the next paragraph.
ULTRAMAN COSMOS is a kinder, gentler version of the above, and was the highest-rated of all of the recent shows. It's fun, but it was kind of a let down for me. ULTRAMAN NEXUS is the closest to a series that would appeal to Americans into shows like STARGATE and BATTLESTAR GALACTICA—set very much in the real world, and has some very deadly consequences for several characters during the series. Recommended for its bravado in turning the genre on its head. ULTRA SEVEN X takes it a step further, but it felt as though it had a lack of focus. ULTRAMAN MAX returns to the basics, but felt bland to me, while ULTRAMAN MEBIUS picked up the ball and ran with it.
Of course, the Japanese-impaired might not get all of the story arcs and dialogue and character development and so-forth, because most of these series have not been subbed or dubbed, which can cause misunderstandings, and misreadings. So, watching with an open mind is highly recommended. Now, one of my favorite series is RETURN OF ULTRAMAN (aka "Ultraman Jack"). One of the reasons is the great character development only hinted at in the earlier series (save for ULTRA Q). In ULTRAMAN and ULTRA SEVEN, you see little of the private lives of the members of the Science Patrol and Ultra Garrison, while there is a lot more in this series.
We get to meet the main character, Hideki Goh (Jiro Dan), before he takes on the powers of a new Ultraman, and meet his surrogate family (his father was killed in a mountain-climbing accident, which is flash-backed in episode 3), the Sakatas, who also are orphans (perhaps from a monster attack). The eldest was a former race car driver, and now owns Sakata Motors, where he hopes to coach Goh as a world-class racer. His younger sister, Aki, is Goh's love interest, and the youngest is their brother, Jiro. The eldest Sakata is played by Shin Kishida.
It is not until after Goh assumes the powers of a new Ultraman—who sought him out because of his bravery in rescuing a boy from a monster attack—that he is sought out by the captain of the Monster Attack Team to join their organization. The stories have a mix of the private lives of Goh and the Sakata's, as well as the members of the Monster Attack Team (MAT). One of the episodes, directed by Ishiro Honda, features the sub-captain, Takeshi Minami (played by the late Shunsuke Ikeda); while another focuses on the dark past of the father of another MAT member, and so on. Then, the series goes through a complete format change in a dramatic two-part episode 37-38, which refocuses the series—I can't say much more without spoilers.
Episode 34 was based on a story written by Shinichiro Kobayashi, who later rewrote this tale, changed and added more characters, and it became GODZILLA VS. BIOLLANTE! It's even set around Lake Ashino! Another outstanding episode is 35, which is a tour-de-force of story and avant-garde photography (and was written by Shin Kishida). Some of RETURN OF ULTRAMAN's monsters seem to get wonky in the last 13 episodes of the series, while the stories and the action remains taught, and refocuses on the efforts of the Monster Attack Team, similar in style to the original ULTRAMAN. The music score by Tohru Fuyuki (ULTRA SEVEN) is a definite plus. The series was shot and produced at Toho Studios, and features a lot of Toho production staff and actors, including guest appearances by Kenji Sahara, Susumu Fujita, etc. Ishiro Honda directs several episodes, including the finale. Well worth checking out—its a favorite of Japanese fans (including Hideaki "Evangelion" Anno and Shinji "Gamera" Higuchi).
The remastered RETURN OF ULTRAMAN series, which was previously available on DVD from Beam Entertainment, is now being released on DVD by Bandai Entertainment for the low price of 1800 Yen per volume (about 1400 Yen from Amazon Japan), which will street on July 23 (in Japanese only):
http://www.amazon.co.jp/gp/product/B003IO8J80/


Check out the promotional video:
http://www.amazon.co.jp/gp/mpd/permalink/mK56618O6QFQS