What if I think the word "nigger" is offensive, but that the words "African American" don't really describe a race but describe a person from two different continents? After all, if a white person has like twelve generations of ancestors who lived in Africa, then moves to America, no one refers to them as African Americans. So clearly the phrase you're really looking for is "black people." Which shouldn't be offensive. Yes, I realize they're not literally black, like coal, but I'm not white like snow, and I don't get pissed off when people call me white.
tl;dr, "nigger" is offensive, "African American" is a stupid term.