The Once Respectable:  James Marsters of Buffy the Vampire Slayer

At His Best:  Tossing child vampires up into the sunlight, killing across Europe for a century having personally felled two slayers and having no regard for human life...

At His Worst: Toss in a violence-curtailing chip, an uncharacteristic love for the slayer he'd previously vowed to kill, and a general apathy toward the heroic crew that while good for ratings, de-fanged the vampire we'd loved to hate in the first place.