Who was Slayed:  group of no-name vampires
Their Faults:  Putting up a fight while Buffy and Angel was slaying them during patrol.
Who Slayed Them:  Buffy and Angel

Who was Slayed:  Mayor Wilkin's henchman vamp
His Fault:  Assisting the mayor with the upcoming ascension.
Who Slayed Him:  Buffy

What was Slayed:  Supernatural Spiders
Their Faults:  Being supernatural spiders, attacking Buffy and killing a cop.
Who Slayed Them: Buffy (with the help of Angel) and Faith.