For those who haven't seen the show, it is about a girl named Elena who is known as "the doppelganger" and the two Salvator brothers, Stephen and Ian, who try to protect her and end up falling in love with her.
This show seemed to have a lot in common with Buffy. She falls for a good vampire who doesn't hurt humans, her best friend's a witch, another one of her friends dates a werewolf- but the main character Elena lacks the power Buffy has. She is constantly the damsel in distress, needing to be saved an protected by others. She has no magic powers, and is undeniably human through it all. Because of this, I find her a very weak and uninteresting character.
The character who I feel is the most like Buffy is Elena's friend Caroline, who gets transformed into a vampire. She starts out very superficial and girly, but as the show progresses becomes a much more complex character. She like Buffy, wants to live a normal teenage life. Both start out as blonde, popular, cheerleaders with lots of friends. But once they start to become involved in the supernatural, they really grow into themselves. Caroline starts assisting in protecting Elena, and thus vampire takeover, while helping her friend Tyler- who is supposed to be her mortal enemy- through his transformation into a werewolf. While doing this, she still keeps her popularity, cheerleading, and fun-loving attitude. She doesn't care what the rules are and does what she thinks is right- very similar to Buffy.
Even though this is obviously not as quality of a show as Buffy is, the character Caroline proves that even in silly teenage television, there can still be a hint of feminism for you to look for.