I'm a generally disagreeable person, so I feel like this could be a long list. Here are my top five:
1) Democracy != voting 2) History is a science, with verifiable and repeatable results 3) Pacifist direct action (a la Ghandi or MLK Jr.) fails 4) History books that lack a 'methods' section shouldn't be taken seriously 5) Journalists are not qualified to report on the topics about which they are reporting