I loved the whole psychology of the series, although after watching Death and Rebirth, I felt like I'd been banging my head into a brick wall for two hours.....
Death and Rebirth is an expansion of episodes 23 and 24 which were kind of recap, but actually more analyses than simple annoying recap.
Random trivia: The two movies were made because Anno was rather unhappy with the ending. He wanted the material in episodes 23 and 24 to be expanded on, but since that couldn't be fit into the timeslot, that was made into a cinematic feature. The second movie, End of Evangelion, is actually an alternate to episodes 25 and 26. That's why the ending never makes sense to anyone ^^
Basically if you watch the series, you want to watch it as episodes 1-26 or episodes 1-22 followed by the movies. I actually like both the endings... interesting alternate ways of looking at the story. But most fans seem to hate the original ending. Too happy and all that. Me, I enjoyed taking a break from all that brain slaughter for some good ol warm fuzzies. I'm going on way too much about this. It's really time for me to shut up now.