Blair is a character that makes you think, Serena is one you want to be friends with.
I agree that Blake has a very sunny, girl-next-door look to her, and she does seem very down-to-earth, but I don't see how that doesn't apply to Leighton. Her beauty is very classic, very universal, but there's something about her that makes her edgier and mysterious without even trying. Plus I don't see how it all has to be about looks. Someone like Ellen Page is incredibly cute, but isn't known for her beauty and style yet was pushed into stardom because of her charisma, talent, and the right project. I hope Leighton will have a similar fate when she gets there.
while Serena is the rebel that's more appealing and accessible in my OP
I think on paper she is, but Blake's Serena is so vanilla.