As I said on Twitter just now, I wish everyone would read Freedom of Religion and the Secular State even if they have to steal it (and I thus get no royalties), because it does deal with all the current hot-button topics: same-sex marriage; exemption of religious employers and others from general laws; the burqa; strong criticism of religion, and how freedom of religion relates to freedom of speech; etc., etc. And it does so in a unified, principled way, grounded in historical perspective and philosophical arguments. Also, while I have my views and - like anyone else - my biases, I try to be fair to both sides of the arguments on these issues.
I don't know of any other book which does quite this job, and this one is certainly the most up-to-date of the contenders, so even if I hadn't written it I'd want everyone to read it so we at least have the same background.
So, go and buy a copy, and tell all your friends to, if you don't want me to starve (note my policy of never asking for donations but certainly recommending that people buy my books!). Or if you don't care about that, at least get your university library to get a copy in so people can read it.
Right now, as I see these issues debated every day, often from a position of ignorance about the arguments, I just wish that more people would read the book, so we can all be on the same page with what the arguments are - hey, and for completeness also read some of the other books with which it takes issue, such as the (very expensive) Ahdar and Leigh book on a similar subject and Martha Nussbaum's more popular go at it.