I'm white and I always say black. African American sounds like you're trying way too hard to be politically correct. I'd only say that if somebody specifically told me to call them that, but that has so far never happened in my entire life. All the black people I know (and I know a lot, I mean I live in NY ffs) call themselves black. I'm white, you're black. What's the big hoopla about.
Black. The accurate one. It's straight to the point, and more inclusive.
African Americans and "Caucasian" sound so try-hard, as another poster stated. This truly is a PC era