On a recent vacation, I took along some serious books: Christa Parravani's Her, a maddening, mournful eulogy for the author's twin sister; Give Me Everything You Have, James Lasdun's egotistical account of being stalked. I took some fluff: Matthew Hughes's funny, Satan-meets-superheroes comedy The Damned Busters; Robert Harris's excellent, wildly off-the-rails thriller Archangel. But only one book left me feeling satisfied and different, in the way that a great reading experience should. It was a novel called Americanah by Chimamanda Ngozi Adichie, and I can't say enough good things about it...