When I watched it directly after finishing the anime, it seemed to me that End of Evangelion was meant to show what was literally going on during the final two episodes that are originally told from the perspective of Shinji's subconscious.
So in the sense that people generally watch it after finishing the anime, and it is meant to more clearly tell the ending of the story, I'd call it the proper ending.
When I watched it directly after finishing the anime, it seemed to me that End of Evangelion was meant to show what was literally going on during the final two episodes that are originally told from the perspective of Shinji's subconscious.
So in the sense that people generally watch it after finishing the anime, and it is meant to more clearly tell the ending of the story, I'd call it the proper ending.
fair nuff, I like the movie too actually even if I'm a bit harsh on it. I havent watched any of the rebuilds though...