It's almost not possible to watch NGE and not have been at least a little spoiled beforehand. NGE is the perennial NGE of every season. I don't remember that much about it, and I didn't even watch it that long ago. One of the earlier episodes has my favorite moment in it, and I like the happy ending.
The last two episodes are the best part of the show. Sure it's strange and not everyone will like it but I think it's the perfect ending. If you're not satisfied with that as an ending well EoE exists.
The people who say the last two episodes sucked are just mad they didn't get a climax that wasn't an introspective one. They are the reasons why Anno made End of Evangelion. People got extremely upset and started sending threats of all kind to GAINAX. Not only were the last two episodes what Anno really wanted, it was also because of a budget issue. I'm kind of grateful to those people that got mad though, without them we wouldn't have gotten such a masterpiece that is End of Evangelion. But the last two episodes in the series aren't bad, they're are just psychoanalysis of each character and how all they connect to Shinji's fragile state of mind. Great fucking show right next to Lain.
The people who bitch lack the comprehension or attention span to dig through the contents of the final episodes. There's rich symbolism and it does effectively tie up the whole series exactly as the previous episodes alluded to.
tl;dr - Just watch them, and actually think about what they're saying.
the symbolism is nge is literally just shit they thought looked cool and nothing more; this has been explicitly confirmed by the staff
Remember, it's just soap.