2. Rupert Giles
Rupert Giles (Anthony Head) is a wonderful character. He is quintessentially British and his dry, witty and sarcastic sense of humour reflects this. Giles - as he is colloquially known - is Buffy's Watcher. From season one until the very end, he is by her side almost permanently, guiding her through her trials and tribulations both as the slayer and in her personal and academic life. He's a kind-hearted, intelligent man who is as phobic of technology as he is keen on books and his knowledge of slayer lore and demons and magic is essential to Buffy's development and well-being. He also has quite a dark past which is referred to, but not deeply explored on screen and he can stand up for himself in both the physical battle and the magical one. His relationship with all of the Scoobies is like that of both a father and a friend and Buffy the Vampire Slayer (both the show and the character) simply would not be the same without him.