The anime is just mediocre. The art and sound are pretty good, combat is decent and interesting, but many parts of the story (especially the foundation of the plot) and most of character development are unbearable. I won't write spoilers, but story wasn't bad at start, it gradually turned worse when the focus was only on Shinji and regular episode was starting as Shinji being depressed, some threat comes to Earth, Shinji tells himself he cannot do it but he manages to beat the enemy, returns and everything starts over again with depression. The anime is also partially experimental (for example Serial Experiments Lain) and the creators played with religious symbolism. I remember one creator saying that the symbols were used randomly or for aesthetics, it didn't really have any meaning behind and they didn't say whether it was just for entertainment or to make the watchers come to their own conclusion. Despite that, there are tons of fan theories, pseudophilosophies and all kinds of interpretations of the symbols, while it was only experiment of creators. The viewer gives the meaning to what he sees, whether he interprets it as an object or gives an essay on why that thing had vital importance.
Overall, the show is ok and most of parts are entertaining, but some aspects regarding the plot, characters and the story progress are unbearable. I understand that many fans relate to the characters in some way with depression, but giving the show too much meaning and affection can become the story of Emperor's new clothes - people glorifying it and making all the hype. There are many popular places and videos which claim various things about this anime, even that it influenced if not all the anime afterwards and many newcomers can fall for that and either accept all the claims or get very disappointed if they don't experience what was written and hyped up.
