My current favorite thinking piece is Martha Fineman's essay Feminism, Masculinities, and Multiple Identities. I began ruminating on it during my concentrated summer research, and keep coming back to it. Fineman asks some important and difficult questions about what masculinities theory has to offer feminism. And she takes on the anti-essentialist critique of feminism, revealing some of the risks of taking that individual identity theory too far. For Fineman, it comes back to making sure we don't miss the structural and systemic gender inequalities that can be lost in our individual rights focus. You can also see her presenting on this topic here.