Only the original series + EoE is worth watching "seriously", rebuilds are sort of a troll commentary on the public reception of the original show, Anno went like "You want more Eva? I'll give you what you want. Are you not entertained?".
They are well worth watching too, but you need to be aware of the context to fully appreciate the message.
The new series is not a “troll”. And clearly watching it you can see as much. It feels like the story Anno always wanted to tell but didn’t have the mental or emotional space to do it in. The story is fully realized and I think it’s actually the most faithful telling of Eva of anything released thus far. I’d even go so far as to say skip the original series and just watch Rebuild. It’s that good.
I think the movies are a lot more focused on just on the main characters, which is a bit of a shame because one of the great things about the original show was that in the later episodes it becomes increasingly more apparent that most of the adults have serious issues too. They're just able to hide it better than Shinji, Rei, and Asuka. I can kind of understand though not wanting to just repeat the exact same content, just with a higher budget.
I have yet to finish the last two movies, but I found the first two a lot more interesting if viewed through the idea that they actually continue from EoE (considering Kaworu's words at the end of 2.22)
Oh, sure, on the first look at 1.11 it felt dangerously close to losing a lot of the character to me - it was 2.22 that made it work, partially because of what I mentioned :)
1.11 felt completely unnecessary to me, personally. It didn't add anything to the original story, and took away too much. The only real achievement for me was the final battle, since the octohedron angel was otherwise a forgettable villain-of-the-week episode.
The sequels that stop tracking so close to the original is where it takes off. I still prefer the original but it didn't feel like a simple re-make at that point.
1.11 was IMO important to prepare the ground for 2.22 - some subtle differences exist and by not following exact the original story it makes 2.22 stand out more. But by itself it's not that great - probably helps a lot that I watched 1.11 and 2.22 pretty much back to back.
2.22 was the peak of the rebuild. I’d have loved it way more if it ended right there. Best character development, most interesting angels (except clocky), Mari has potential and wasn’t another caricature, all downhill 3.33 was little more than a drawn out and more boring episode 24 with 2 interesting fights.
That's more the weakness of the 3rd than the 4th. The third movie felt like there was a whole volume between part 2 and part 3 that was missing - I get the appeal of telling the story from Shinji's perspective and starting in media res, but you can't just use terms like "failed infinities" and the "chamber of guf" without a little establishing context.
The 4th brings it back somewhat, but ultimately the finale is still the typical Eva "here's a bunch of religious babble half-explaining what happens overlaid with crazy imagery" which imho had its last hurrah in EoE.
3.0 was garbage except the opening rescue scene and the end battle, I would not recommend it at all. The 4th has too much eye candy that wasn’t even babble.
As cheesy as it sounds, afterwards I sort of felt like the bad cg (and copy pasting assets) was intentional. Maybe it was meant to contrast the eva specific parts with the rest of the regularly animated sequences with human characters. The scene that made me think this way was near the end the giant Rei head exploded into a bunch of 3d eva models (about 2:20), where afterwards they decided to animate the contrasting scene with humans without 3d, which was probably so much more work that I felt it must have been intentional for some reason.
