Problem is that while I don't feel much sympathy for Cersei, I still consider her 'good' character. I mean... she is a bitch - but a very well written bitch nonetheless. While, as for Daenerys, I don't perceive her as well-written character.
Well i can agree there, she is written to be hated and i hate her because of it. But in effect she is the opposite of Daenerys to me, where as Cersei is essentially just cruel and spiteful with no real redeeming qualities (mind you its mostly cause she picks on Tyrion who is my second most favourite character in the whole series), Daenerys is just..well lets just say she's AGoT's version of Jesus. Though i believe her arc, her personality would work much better if her brother was still alive, since she is effectively his foil, she is not really Aegon, but rather a female version of Rhaegar. The difference being that she has everything handed to her too easily, so unless she actually ends up enduring alot of shit, more than ADWD i mean..yeah its too convienient for her. The whole Aegon reference is really just because she has dragons, but as a character, she's mostly Rhaegar basicly.
Still, for the moment she has Mary Sue qualities and i hope she outgrows them, but she is a good character, she actually stands out from the cast of..well not-so-good-people so to speak, but sadly too much so that it becomes comical again.
Daenerys is an awful character, and what happens to her is also completely unrealistic and out of tune with the rest of the saga. She should have been murdered long ago.
Same as above really, its not so much that she is a bad character, she just feels too..good, too pure, too nice compared to the entire rest of the cast who just isnt. But if you consider where she is and what she does, its hard to really see her being anything other than "good" which makes her a sort of messianic archetype. If you took her out of Essos and put her right back into Westeros, i bet she'd be a whole lot different because the problems in Essos arent the problems in Westeros, the whole mass-slavery and "hero of the people" thing she has going would be far less effective in the seven kingdoms which might allow bad qualities to surface. I believe she just needs a foil, or a serious obstacle that simply cant be overcome without compromising her ideals to make her grow. As said before, her brother's death was a mistake in retrospect since he would serve a fitting role as a foil to her idealism.