I have always been a fan of Cloe's up to the last season. Mostly because she had no powers and used her wits, especially in the early days of Smallville. She was cute and a kind friend overall to Clark. Even her backstories involvng her Mom and family was nice and not overdone.
Heck, even when she did get some powers, it wasn't that bad. But then she started being more manipulative. First she destroyed Jimmy emotionally last season just in time to destroy Davis, whom she was trying to keep sane and normal. Then she has been tracking her partners without their knowledge. I don't think Oliver ever did discover it was Cloe that put that tracking device in his belt buckle. She put Oliver in a life or death scenerio. And she somewhat belittles Clark for not trusting her and I don't blame him for not trusting her.
Is there hope for her? In "Warrior" I saw a glimer of her becoming more like old Cloe...until she started flirting with Oliver. Oy vey NO!