Genre(s): Anime (heh), Mecha (involves robots, or in this case cyborgs), Shonen (aimed at more mature males, hence: violence/gore (lots) nudity (an unhealthy amount).
*Sigh*
Did I mention Evangelion contains a mish mash of metaphysical randomness and a fine dose of Christian symbolism?
With that in mind, let's proceed.
The first episode of the anime begins with a battle. We see how the most powerful weapons are useless against the Angels (the series' main antagonists). Then we find our reluctant hero, Shinji.
He is one of the "Children" (the second one, actually) who are able to pilot the Evangelion (huge cyborg battle suits).
And thus, the show begins. But the Evangelions' are no undefeatable super weapons (at least, most of the time). We see them sliced and diced, blown to bits and voila, repaired again (the price: a hefty chunk of Japan's budget).
But Evangelion does not stop there. Besides the interludes where we are given more of the characters' backstory, we are treated to the psychological torments that plague the pilots of the Evangelions: Shinji in particular (he is what we would call a typical emo kid), Rei (she is so emo to the point that her character is as lively as a doll) and Asuka (grossly extroverted, a big contrast to the other two).
Anyways, there is the usual Christian symbolism here: Tree of Life, Lance of Longinus (a.k.a. Spear of Destiny) we see an Angel crucified (any point here that they were trying to make is beyond me) and etc.
Violence. Yes, heaps. Mutilations, dismemberings and all that. And they get rather gruesome, too. Not to the forget the often pointless nudity/sexual references: There is a scene where Shinji visits Rei's apartment. Apparently, no one is there. But then she suddenly comes out of the shower, surprises Shinji and what do you know? He trips onto her, and lands with his hands on her breasts. Right.
Oh well. Up to you to decide if you wish to wade through this stuff to reach the good parts.
It can be said that Evangelion displays its characters with all their human flaws, in full glory.
You might find Evangelion in its totality (metaphysical monologues and all). I only found its battle scenes and backstory entertaining. And Evangelion is strongest where we are told of the backstory behind the Angels' appearances, as well as the story behind the Evangelions.
I only found one interesting thing at the final scenes of the movie End of Evangelion (Spoiler):
Shinji, instead of choosing to become "one" with the rest of humanity (who has since been reduced to primordial soup), chooses individual existence. Quite interesting, as it takes a good swipe at Hindu/Buddhist doctrines of the final goal for all humans: Oneness (which is Pantheism, by the way).
I guess Shinji doesn't like Nirvana.
So, my overview of the series (and movie):
Interesting story, engaging battle scenes, characters are developed rather well. But the the most terrible parts are the internal monologues, while not all bad themselves, were rather annoying after a while.