I honestly have already settled on my three favorites based on their personalities. I haven't delved much into the lore of Forgotten Realm in a very long time so this is strictly from what I've seen so far.

Astarion: Not a huge fan of this one. He's not a flat character but the fact that he starts off putting a knife to my character's throat, I don't bring him along on the adventures. He can't be trusted.
Shadowheart: Her only redeeming feature is the fact that she can cast healing spells and even that makes it tough to justify keeping her in the party longer than I need to. Her banter with Lae'zel can be pretty humorous at times and it's nice to see her get verbally slapped but, she comes off as a pain through and through. She's rude, insulting and kind of weak in a fight. Her healing is her only pro feature.
Lae'zel: Lae'zel is a realist and a self-preservationist but I would not say she's evil. She sees a threat and is rushing to take care of it by any means and, she's actually pretty open-minded compared to most githyanki that I've read about. They'd rather slit your throat than work with you so I wouldn't say she's evil so far, more like she's just trying to make best of a bad situation.
Wyll: I just found this guy and I'm already loving him so far. His sense of justice matches up very well with my characters and they tend to agree across the board. I mean, he doesn't have a bit of a secret that gets spoiled by the loading screens but, who doesn't expect that from a warlock anymore?
Gale: By far, my favorite character, no holds barred. He's humorous, conceited and hiding a few nifty little secrets of his own. Honestly, they did an amazing job with Gale's secret and makes me a little sad that they didn't give Wyll the same treatment because finding out Gale's secret was pretty shocking and almost caused me to get my whole party killed without realizing the cause.