There is a huge thread and poll about that here:
Sorry for my hasty rudeness, I guess it was a case of unfortunate link placement... placed on the bottom without comment it looks a bit spam-ish.
Personally I like Linda Goodman's zodiac explanation best: http://www.mizii.com/englishwiz/library/names/zodiac/contents.htm
She is so funny to read and she goes quite deep beyond the stereotypes. For example most people describe Virgos as these cold, analytical beings; LG is the first one that sees their secret dreams.
I'm very much into astrology and I've found this to be the most accurate of anything I've read before: