Asuka, I liked her a lot when I was younger.
Problem with her is, she's smart, energetic, hot, etc....but later in the show she trades places with Shinji (per directive of the script). And as Shinji becomes more of the 'leader' of the group, comfortable with attention, assuming of his role in 'society' and confrontational (partially because of Asukas presence and help), she starts to spiral down into a state of depression and doubt.
And while I understand WHY it happens...it also seems to happen for no real reason other than they need to set her up to be a 'opposite force' for Shinji and no more than a visual character that stands next to Shinji to try to make him look stronger by having another character be weaker as the show goes along.
And so, yes, that's my long way of saying I like Asuka. But its sad that she has to be a self-loathing, suicidal bitch just so Shinji can blossom into the savior of the world.