Lae'zel is my favorite. Her story feels the most authentic of what I've experienced and it feels like she is adhering to her Githyanki creed.
Wyll seems lame. Gale is okay, but a human Wizard is eh...it would have been better if he were a Deep Gnome. Astarion is okay, but a little too over the top. Feels like bad acting sometime.
Shadowheart seems like she has a lot of content, but Trickery Cleric isn't the best and it suffers more from some things not being able to translate to a video game.