I'd leave World History to college. It's just too large a subject to do a worthwhile job of in high school, particularly in AP, where they're going to cut you off with ~9 weeks to go in order to prep for the AP exam.
AP European History (Reformation to WWII) changed my entire worldview. Public school history classes that are stories of "us" are loaded with propaganda, with actors often reduced to heroified caricatures. European History isn't about us, so it's presented in a balanced way. The actors become human. Once you see historical people as something like yourself, it makes the study of history far more compelling.
I never had much interest in the subject until I took this class my senior year. I'm currently reading US Grant's memoirs, plus
The Hinge Factor: How Chance and Stupidity Have Changed History.
