* Translated from Japanese to English
o Ultraman
o Ultraseven (actually not a direct translation, but often a rewrite)
o Ultraman Ace
* Produced in English
o Ultraman: Towards The Future (a.k.a. Ultraman Great)
o Ultraman: The Ultimate Hero (a.k.a. Ultraman Powered)
o Ultraman: The Adventure Begins
Also one of the recent and most well regarded of the Heisei Era (A period that basically covers..I want to say from mid 80's through 1999) series Ultraman Tiga was dubbed (HORRIBLY!) for the Fox Box kids line-up on Saturday mornings.
By the mercy of the gods, the show was canceled AND there were DVD sets put out with full and accurate subtitles and the actual Opening and Ending sequences and music intact. These can be found on Amazon.com if you want to check this show and be able to appreciate it as it was intended.
Tiga and Nexus are my personal favorite Ultraman series. Tiga has a classical feel but it's also pretty modern. Nexus has a much darker tone but isn't dumb, cheap, and nihilistic about it. It simply presents a world that is very much in need of the light of hope that Ultraman represents.