What do you need explained exactly? *Evangelion fanatic*
i am not a fanatic >D well i don't get the ending how everyone pops and why the angel thingos stab themselves and ray is human is she ... and how were the eva pilots chosen.. 
thats the most confusing
***SPOILERS***
Everyone "pops" because of the Human Instrumentality project, initiated by SEELE, which merges everyone on Earth into one giant conscience. The melting thing is basically because everyone's physical selves disappear, leaving only their "souls" or whatever the hell it is.
The MP-Evas stab themselves because it looks cool. Seriously. Canonically, it's to initiate Instrumentality or something.
Rei has a human body (constructed with the DNA of Shinji's mother), but she is in fact also the vessel for Lilith, the second Angel.
***END SPOILERS***
OK, I just feel like asking this question:
Do you ever tend to like/dislike an anime series purely due to its music? -- It happens to me sometimes.
Shakugan no Shana's only strong point was its OP.
I thought Shana was an ok series until after the twins. Relatively good at being a visual novel adaptation until it started getting...er...repetitive.
Can't empathise with the music thing either, although I admit I've watched a few Anime just because I liked the theme song. >_>