Interesting side notes about Spike:

From http://www.buffy.com/player_bloody.shtml
A cocky vamp from 19th century England, Spike got his former (pre-bloodsucker) name, William the Bloody, because of his bloody awful poetry. However, in 1880, the sensitive lyricist was sired by his immortal lover Drusilla and got the name "Spike" because of his love for torturing victims with railroad spikes.

From http://www.boadicea.net/buffy/name.htm
William decided to call himself "Spike" because he enjoyed torturing people with railroad spikes. It is interesting that one of the people who mocked him and his poetry, when he was human, said "I'd rather have a railroad spike through my head than listen to that awful stuff" (re: William's poetry). It is reasonable to believe that William, once turned, did exactly that to the haughty nobleman who had mocked him.

More on Spike's past:
http://www.ancientartofslaying.com/BuffySoundOffHall/Buffysoundoff7.htm
http://www3.sympatico.ca/jenoff/btvs507.htm