8. Anya Jenkins
Anya (Emma Caulfield), a former vengeance demon, is a quirky and highly socially inappropriate girl. The love of Xander's life, who had spent most of hers as a brutal man-killer, simply did not know how to act in social circles. Had she been an ordinary human, her 'symptoms' would be like those of someone who has Asperger syndrome - saying the most appalling things possible in any given situation. But, because she couldn't really help it, this actually made her more likeable. Anya becomes a fully-fledged member of the Scoobies and helps with research - sometimes even getting her hands dirty in battle. She fights in Buffy's final fight against the First Evil, where she loses her life by virtue of being cut effectively in half by one of the First's minions.