UltraSeven's stuff is something to go to if you want something a bit more serious and...I can't believe I'm going to use this term to describe this but....'realistic'
What I mean by THAT is, UltraSeven pretty much had his bag of tricks, and that was about it. He never pulled new powers out of the ole bum as the plot demanded, though one could argue that Ultraman didn't either, and he was pretty consistant. The real point of it though, why I say realistic, is because...
Ultraman is less sci fi and more Fantasy. It HAS sci fi in it, but the general tone of the series edges towards the fantastic.
UltraSeven is pretty much hard Sci Fi, zero magical anything anywhere. His universe would mesh well with, say, old school Doctor Who or Star Trek. Ultraman told way more, and different, stories.
However UltraSeven has one advantage over ultraman and one disadvantage.
Seven loves PLOT. It dedicates itself to plot, often to the point where Seven himself is barely featured. This is both a good and bad thing, to different people. The epic fights ARE epic, but they can be few and far between.
Ultraman, more often then not, was merely building up the new wrestling match between our hero and the monster of the day. There will almost ALWAYS be a neat little fight, though rarely will Ultraman struggle in it and rarely will the plot advance beyond "NEW MONSTER! SHOOT IT UNTIL WE CAN'T! ULTRAMAN!"
This isn't always the case, but it happens more then not.
Nexus, on the other hand, is a dark, wonderful, tightly plotted series that's a roller coaster from beginning to end and has some of the best fights in the franchise. Sadly it got cut short.
Max is really really REALLY generic to me, but it is a good little jumping on point. Purely because you could start at basically ANY episode and it'd make just as much sense, depending on if you know the set up (Guy can become giant super hero to fight monsters)
Mebius is an odd middle ground of Nexus and Max, as it HAS a very well told plot that builds up over its run....AND its episodic.
