One of my standbys is "historiography" - the way that historical research is conducted. This refers to both the methods of research and the philosophy behind them.

I like this word because a lot of people want to talk about this subject, but don't know the right word for it. It's also an important topic. For example, a lot of our knowledge of anything from before about 1850 (in Western history) is based only on the writings of rich people, because they were the only literate people. Therefore, historiography is flawed when we talk about the lives of working class people from those times. We basically only know what rich people thought of peasants, which could be very biased and inaccurate.