To be completely honest, I wasn't captured by it until episode 16, but before then I thought "yeah this is a nice 7-8/10 mecha anime with some good themes of depression, some visual motifs, and a nice vibe", but then after I watched the last 10 episodes I realised that the first parts perfectly set up the payoffs that happen towards the end. The last 10 episodes + End of Evangelion are one of the best examples of flawless anime in my opinion (maybe with the exception of the series ending).

Everything that happens has some prior hints or meaning, which makes the earlier parts retrospectively better, and the pasts of the characters are reflected in how they act as people now. They all have experienced trauma, loss and depression, and you can see that how they act now is a product of their tragic backstories. What makes this anime truly special is its use of psychological elements such as Freudian principles, which are prominent in the anime, and how that makes the characters interesting and great. It isn't exaggeration to say this has the best-written characters I've seen in an anime.

It's very weird at points, which may be one of the main reasons that it is so divisive. This weirdness can either land or fail, and for me it works most of the time, but there are a couple bits that feel a bit too fan-servicey, but that's maybe 2 or 3 scenes in the whole anime. I would say don't watch it within 50 metres of a parent or younger sibling who could look over your shoulder because out of context it looks strange.

The way it tackles themes of depression, trauma, the value of life, and the lives of humans are done very well throughout the anime and it can mean something different to you each time you watch it and can mean different things to different people. You'll probably enjoy it more if you've ever been very depressed, but I haven't personally and I loved it.

The ending(s) are also great. I appreciated the experimental ending of the series, but End of Evangelion (the movie), which gives the outside context of what is happening in the minds of the characters in the series ending, is my favourite ending of all time, and the Rebuild ending plays it more safe but it's also good.

It's the kind of anime that leaves you empty and feeling either sad or happy for a while after, and seeing the characters can leave you with a feeling of emptiness.

This isn't nostalgia by the way, I watched it this year, and it's still one of my favourites.

Basically, I'm saying to watch it. Expect it to be unusual and experimental, and try to be open to what is going on because everything makes a little bit more sense later. In your confusion after episodes 25&26 don't go to google to find out what happened because it's explained more in End of Evangelion. After that you can look up the stuff you don't understand. It has some unique vibes, great setting, great characters, and tells one of the best stories in anime, at least in my opinion.