Buffy the Vampire Slayer
The main character was Buffy Summers. She was played by Sarah Michelle Gellar.  Buffy was an ordinary high school student in the fictional city of Sunnydale, California, except for being a "vampire slayer."  Buffy's Watcher was a British man named Giles.  With the help of Giles and her friends, Xander and Willow, Buffy fought a different monster every episode. (aside from the main villains of each season).