Just picked up "50 Battles that Changed the World" at the book store. There's a lot of these types of books out there. I've got a bunch of these books on my shelf and they all seem to come at it from a different angle.
So, in the winter doldrums (and because I'm sick of arguing over who sucks worse, Marty or Dunner) I pose this question...
In your opinion, what millitary battle has has the greatest impact to the course of history?
I'll also throw out a friendly reminder that religion and political debates are verboten so please consider this when disussing the effects a particular battle may have had on religions and political systems. This is intended to be a discussion of history not a debate about either one of those subjects.