It is my job to answer the question : "Why Narcissa?" for you, correct?
Ok. Prepare for me to make a Narcissa-convert out of you.
Now that I think about it, I don't really have a reason for liking Narcissa. She just sort of grow on you I guess. Maybe I should tell you how I see her. She is:
Misunderstood. She's not pure evil, or the daughter of Satan (but maybe Lucifer's wife...).
Not entirely helpless. She can fend for herself, she's just stuck under Lucius' very expensive and heavy iron-tipped, dragon-hide boot.
Beautiful. Very Beautiful.
So those are my reasons. Tell me if you have something to add. And if you'd like to refute me, do so please.