Best introductory texts in moral philosophy?

Continuing with our series (see here and here), I now invite readers to name what they think are the best introductory texts in moral philosophy (including normative ethics, metaethics, and moral psychology; I'll do politcal philosophy separately). As before, don't just name a text, but say something about why you think it's particularly notable or valuable.  Although you don't have to sign  your comment, I do think signed ones will carry more weight with readers.