This movie summed up everything I've always known about religion. My family raised me Christian but luckily my Grandmother studied ancient Sumerian cultures and informed me about Horus as well as other Gods sharing key characteristic to Jesus.
Another good point to be made is how in the end, no one is right. Religion, that is. Each is just a story, made to remind us of the importance of the Sun and Cosmos alike. The problem here is Christianity was the first to be backed by politics..that is what made it into the monster we see today ;)
If we compare our society all the way back to when Constantine made Christianity the official state religion to ancient societies, from the Sumerian's to the late Greeks we see a very thin gray line. What has occurred here? Well, very frankly it seems as if we lost our curiosity. This is not to say great things have not occurred since (Nietzsche, I appreciate your perspectives). However, I am speaking of our will to seek the truth behind our planets mysteries and beyond.
It seems when people base their life around a silly story they loose interest in these things because "God" will take care of it. "God" knows all...
Well once you accept there is no God, and we are in fact here all alone, you will realize there is a lot to be discovered and much to be explored, here and in deep space.
The real history of the development of Christianity and the Christian god is much more interesting. The discovery of the Ugarit text has led to an understanding of many of the gods in the Canaanite pantheon. Turns out that Yahweh is just one of the 70 sons of the king (El) of the gods (Elohim). It really gives the Abrahamic god a much more interesting mythology when he's placed among equals like all the Greek and Roman gods were.
Like any distributed source of information, zeitgeist needs to be fact checked. However, you are begging the question and assume that "most of the 'facts' cited in this film... aren't" because a few points are inaccurate. I'm sure if you fact checked every claim in this documentary you would find that many of the facts are inaccurate rather than most of the facts, a huge difference. The reason I think this documentary is great is because it very eloquently demonstrates many valid arguments against religion. There are few substitutes for this documentary. And I'm sure your right, the real history of the development of Christianity probably is more interesting. But honestly though... what types of historical information can we trust enough to actually fact check history with even remotely close to 100% accuracy. I love how you mentioned the Ugaritic discoveries though =).
I too like the Zeitgeist Movie for the kind of in-your-face shake-up-your-perception... But after doing some reading on that link Mike posted, I'm not just blindly pointing to everything in it as 'fact.'