I'm boring with my favorites.
If I were to say off the top of my head, I like Ghazali's Inner Dimensions of Islamic Worship
, Al-Maqasid: Nawawi's Manual of Islam
(which is indeed as dry as it sounds), Reflections of Pearls
, and The Accepted Whispers
. The first two are more or less reference works mostly on "the pillars" of Islam, the first (obviously) having a little more to do with intentions and mindsets, and the latter having more to do with the acts themselves (but there's a lot of overlap). The latter two are primarily just books of prayers. Honorable mention to Aisha Bewley's Muslim Women: A Biographical Dictionary
, which again, obviously, is more a reference work, but one that is pretty heartening in its sum total.
I don't personally really like applying a scale of moderate-->extreme or conservative-->liberal when it comes to exegesis or interpretation, which is why while I don't really agree with them on a lot of points I'm comfortable suggesting Wadud and Barlas as reading. I come at things from a point of view that says so long as there is a clear, knowledgeable effort being made to not misrepresent
the Qur'an or misrepresent
the hadith, a work is valid. (Although I know I'm kind of stretching the tradition of the definition of legitimate scholarship there.) The only thing, IMO, is to go into a work understanding its bias and understanding that it is an opinion, not a big capital-T Truth. Though I do totally get wanting to stick with non-extremes if you feel you don't really have a foundation for sorting out what's what ... it's just that the waters are a little muddier than to be able to do that and have left a lot of reading materials on contentious issues such as gender or sexuality.
(P.S. - The Bullock book is great.
I'm glad you found it ... hijab is such a side issue that becomes so easily centralized that I usually only bring it up if it's asked about specifically, but it is worth a read.)
(P.P.S. - If you have a LOT of time on your hands, there's a three-volume set of history books on Islam called "The Venture of Islam" which does a lot to contextualize the place of the religion in the world. But, again, it's huge. There's a similar smaller work called "A History of Islamic Societies," but I've not read it.)