I like them all and am fairly certain that almost everyone has judged them as this or that without having the slightest idea who they really are. We get some snippets of who they are here and there in EA, but I think these characters are much deeper than any of us thinks.
And I've heard a lot of complaints about how they are all so grand with big issues and none of them is normal. What I don't see a lot of is people saying, "Um... I think that's intentional."
Do you think that Tav is the ONLY one of the origin characters who is special? Right now, it seems like wherever you go, Tav is the shiz-nizzle. Tav gets everyone's attention, everyone is like, "You're my hero," even Minthara if you play your cards right. Gut even says, "Now here's someone special." She doesn't say you're another True Soul. You're "special" it seems to everyone, and your tadpole is amazing.
But why were you chosen to receive the tadpole? Why was Gale? Why was Lae'zel? Why was Shadowheart? It is mentioned a few times that every one of the origin characters was chosen. It wasn't just Tav. So, why would the Absolute, or whoever's behind it, choose random, ordinary people to be some sort of Special True Souls? No. He/She'd pick special people who have deep, special backgrounds and powers. Why? Who knows, but it is certainly to fulfill some super grand purpose.
This said, my favorite is probably still Lae'zel. Ironically, my wife and kids hate her so much. I like her because I don't see her the way a lot of people see her. They see her as some brute annoying, nagging thug who is cutting and condescending and nasty. I see her as a desperate, hurting individual who is fighting to overcome the weaknesses inside herself and who is trying desperately to escape a fate she has made for herself; not just the tadpole, but whatever it was that she did to become what she is now. Lae'zel has a lot more complexity about her than people think, I believe, and though she definitely does not share my beliefs, I like her nonetheless.
Astarion is actually my second favorite. I didn't like him at first, but he grew on me quickly. I also think he's underestimated. I think he does it on purpose, and everyone just thinks he's some flamboyant idiot. I'm fairly certain he either IS Cazador, or he's much more than he tells you that he is; perhaps a rival of Cazador's or something. What I think is someone made a deal with devils in regards to him, and it is written all over his back in his scars. The mind flayers chose him for a reason, so I'm thinking that he is lying through his teeth a LOT during EA. He's playing a weak jokester who is subservient and is desperately in need of your help to escape his former master and just wants to be your friend and for you to trust him, but whether he actually is enslaved by Cazador or not, he's using you all the way. You trust him, he'll literally bite you in the end. No doubts. He's evil to the core underneath it all. Is he savable? Maybe. Either way, I think he's totally underestimated.
Besides, he makes me laugh. I love the "How would you like to die," conversation. "Strangulation. Poisoning."

Shadowheart is probably next on my list. I'd like her more if she was a bit less witchy. One minute she's all like, "Hi friend. Let's talk." The next she's, "Kiss my butt! Don't talk to me. That's my business." But, I figure, she's just unsure of who she really is. She's a Sharran who is finding out that she's not really a Sharran. No doubts. She feels guilty about all sorts of things and finds herself caring for people like the tieflings. She's no Sharran, but she thinks she is and is tormented by it. So, I like the conflict, even if she is rather obvious about EVERYTHING.
I think I'd like Shadowheart more if they actually made her entire plotline more subtle and UN-obvious. If we met her in the pod and on the beach, and she was wearing normal armor that didn't scream Shar, and she lied and said she was a cleric of some other trickery god or goddess, and she didn't make it so plain she had nothing but contempt for Selune ALL the time, I think the big reveal would be much more shocking and fun. If she was sweat and nice and you just love talking to her, and she's sweetly lying to your face every time you chat with her, and you are totally clueless, and you're thinking she's a cleric of some good god or goddess of trickery or whatever and then suddenly she hits you hard with her reveal? Yeah. That would have made her so much more awesome to me.
Like, "Hi, I'm Shadowheart. I'm a cleric of Meliran Tiromen, goddess of bards and such. Her domains are trickery and life and light. Blessings from Meliran upon you."
Later, "Meliran doesn't approve of Selune, actually," Shadowheart says sweetly. "She thinks Selune is a moon-witch. Hah! The way she looks at things, Shar is like an older sister who was just enjoying herself in her room in the peaceful dark. Suddenly, Selune bursts in screaming and fussing and shining her bright light in her face. Then when Shar got mad, Selune screamed to all the other gods and got them to side with her. Now everyone hates Shar. That's how Meliran views it. People think Shar's at fault for everything, but it's really Selune, ya know."
Then later, "I'm a cleric of Shar."
"What?" But... dang! You're too sweet to be a cleric of an evil goddess."
"Well, you wanted to know," Shadowheart says, now acting totally uncharacteristically vicious. "There it is. I serve the Mistress of the Night. I am a cleric of the Goddess of Loss. You've convinced me to reveal my biggest secret. Now. What are you going to do about it. Are you going to try to kill me? If so, let's get it over with." Then she grips her mace and shield and prepares to kill you. You have a choice, either you accept her for who she is or kill her. No in between.
Man! What a shock that would be. Sure, she could drop subtle hints here and there and not be sickly sappily sweet the whole time. I'm not saying that. I'm just saying that I think she'd be much cooler if she was a normal person in the beginning who is nice and acting all good and soft-hearted only to find out she's been lying to you the whole time.
Gale and Wyll, I want to like them more, but maybe I just don't know enough about them. Of all the characters in the game, I trust Gale the least. I'm fairly certain he's a Netherese mage who is just looking to gain as much power as he can for some totally diabolical scheme he's got concocted, and I'm fairly sure he's a two-faced liar manipulator. But then, every time you do something bad, he disapproves. So, is he good? Hard to say. I just don't trust him in the slightest.
And did anyone else notice that Gale is the ONLY origin character that you do NOT immediately connect with in terms of the tadpole? You connect with each and every one of the others, but not Gale. What's up with that? Is his maelstrom of anti-magic preventing you? Is he even infected? He seems to be. He acts like he is, but is he really? What if he is actually not infected, and he's just using his tadpole to get close to you to find a way to control you and manipulate you. But then, he can also gain tadpole powers... so...
And Wyll is a nice guy and all, but he also seems to be lying a lot to me. I think he's a huge fake as well who WANTS to be this hero but he really isn't. Deep down, he's a monster in his own way. Maybe I don't like him because like Gale, he seems fake to me and he seems like he's pretending to be good just so he can manipulate and control you.
I could, of course, be reading into all of them too much, but whatever. That is my ranking of the characters and why.