Dorothea all the way. She feels the most... human, I guess? Not to say that the other characters are all just tropes, they're all really interesting characters, but Dorothea feels the most unique. She's sassy and flirty, but at the same time she's very compassionate. She seems to actually care about the people caught up in the war. Not to mention her voice actor, Allegra Clark, is pretty cool too (and also voiced Shamir, another one of my favourite characters).
Also, on another note, is there gonna be a poll for people's favourite faculty/Knights of Seiros character?