I actually just finished watching it (along with end of eva) the other day. Honesty, I think it was meh. I enjoyed the character study and brutal eva fights, but the whole thing was just a tad too disjointed for me. I understand why this happened, the creators depression coupled with the budget running out made the show a bit of a mess. Don't get me wrong, it had plenty of good stuff. Like the aforementioned character study and fights, and the religious symbolism and puzzle piece plot provides plenty of food for thought. In the end I'm happy I watched it. The series was made as an antithesis to anime at the time, which was just a bunch of escapist, self insert, wish fulfillment, and the show is a cultural landmark that has influenced countless anime. However, it's a bit too "off it's meds" for me to really consider it good.
With all that in mind, I'm actually looking forward to the rebuild movies, which I will watch after the last one is released. I've heard them described as "no less horrific, just more cohesive". The original series had enough good in it that I'd love to see what it's like when it's taking it's meds.