[GrandComplete]

Hmm the original 1966 Ultraman I think decent way to start off. Introduces alot of elements that are still reconizable to this day.

Tiga is similar to Kuuga in which was a revival for the franchise and is widely popular for being very innovative and different style from the clsssic Showa.

Nexus is "dark" series but the mature themes are balanced by a very unique take on Ultraman and the show at the end of the day is telling you to not give up inspite of the darkness.

Mebius is an anniversary season with actors returning and storylines from past shows being brought up. Despite this Mebius anniversary elements in the 1st half is relatively restrained as such time is spent more on the new characters then the old. In fact I've met more people who got into Ultraman through Mebius then any other show.