What's the greatest fight you've ever seen?

It can be boxing or MMA, or heck, even a streetfight. A few that immediately come to mind are Clay Guida vs. Tyson Griffin which was absolutely brutal (personally, I thought Guida got hosed by the judges), Sakio Bika vs. Jaidon Condrington in the Contender, and Manny Pacquiao vs. Erik Morales. What do you think?