I never build the Pyramids, as I like to play either despotic conquest (no need to change the type of government there) or hi-tech conquest (switch to republic early - it's easy to develop - and then stick with it).
For a nice game of hi-tech conquest, Women's Suffrage is a must, and the Hoover Dam sure helps, too.
My vote goes to WomSuff, though I always build Bach, too.