Let's see:
"Next" by Michael Crichton
"An Essay Concerning the True, Original, Extent and End of Civil Government" by John Locke
"With Wolfe in Canada" by G.A. Henty
"St. Bartholomew's Eve: A Tale of the Huguenot Wars" by G.A. Henty
"End of the Spear" by Steve Saint
I like to keep various books going according to my mood, plus I have to squeeze them in with work and playing with the kids, so chapters of different lengths are good too.