My greatest killing spree was this one time in Solitude. I got bored so I went to the Thalmor Embassy, picked the lock and opened the gate, then ran off. I proceeded to transform into a werewolf, slaughtering everyone withing the embassy. Then I ran down to the hidden stormcloak camp by the river and killed everyone there (#empire4lyfe). I believe I killed almost three dozen people by the time it ended. Then I went to the city, and the first thing a guard mentioned was hearing a werewolf howling. Good times.