The thing about the numerous manga versions of Eva is that they are all telling the exact same story, but in different ways. Sadamoto's work is the closest to the original show, with only a small handful of changes being the only difference between the two.

Then you have something like Neon Genesis Evangelion: Campus Apocolypse, which has Shinji and friends wielding guns to combat the Angels - who are more like bean counters wanting to rebel against the system than the Lovecraftian monsters they were in the show.

 

Personally, I would say both the Rebuild movies are worth watching just for that scene.

Well, that and getting to see how awesome battles are when Anno has an unlimited budget instead of the shoestring budget the TV series was made with.

 

I would recommend reading this version (NSFW site) instead of above. The smut was scrapped and some new scene were added, making the story more interesting and compelling.

Evangel Notes: Requiem for a World is a crossover beetween EVA and Notes, a short novel by Kinoko Nasu. It's interesting and quite well written.

 

Hmm, looked through volume 1 and I have to agree. I thought the NSFW stuff was completely out of place, anyway, so I'm glad they scrapped it. The new scenes are pretty cool.