Just a somewhat random list, in no particular order:
* St. Teresa of Avila, particularly the Autobiography. Way of Perfection and Interior Castle are also good. The strength of the Autobiography is that it is more biographical and less advanced, and therefore more accessible.
* Lady Mary Shepherd, An Essay upon the Relation of Cause and Effect. I would identify this book as the single philosophical work that is typically unread that most needs to have a wide readership among philosophers. (It needs to be supplemented, though, by some of the essays in her book on the perception of the external universe, since they clarify things that aren't wholly clear in the earlier work on causation.)
* Iris Murdoch, especially Metaphysics as a Guide to Morals. The Sovereignty of Good is also worth reading. She also writes fiction, most of which I find only so-so (and some, like The Sacred and Profane Love Machine quite bad); but The Black Prince is fairly good and The Green Knight is quite good. But there are lots of her books that I haven't read. One I haven't that is supposed to be excellent is her fiction work, The Bell.
* St. Edith Stein, Finite and Eternal Being. Frankly, some of this work is over my head; I just don't have the background in Husserl and the early phenomenologists to catch everything. But for all that, it is an enjoyable read.
* Martha Nussbaum, particularly Love's Knowledge. There's way too much Henry James, and Nussbaum makes the mistake of agreeing with James's utterly absurd critique of George Eliot, but I suppose there's no accounting for taste. This work discusses ways in which literature, as such, can contribute to philosophy. Also good is her work on Greek tragedy and moral philosophy, The Fragility of Goodness. Some of her newer work is not, I think, quite so good; one of Nussbaum's weaknesses is a tendency to try to rig the argument (and interpretations of alternatives) to get conclusions she already deems right, which has, I think, become more prominent in recent years. But she's still well worth reading.
* Dame Julian of Norwich, Revelations of Divine Love. How could one not like this book? Alas, she is often misinterpreted. For instance, her famous tendency to call God 'mother' is easily misunderstood: it is the Second Person of the Trinity that is Mother, and is called so entirely in relation to us: Julian sees the essential properties of motherhood as "natural love, wisdom, and knowledge" and rightly recognizes that these are all in Trinitarian theology technically appropriated to the Son in His relations to us: the Word of God, as the Wisdom of the Trinity, grounds our existence by encompassing us (He is that in which all things cohere), and, through His loving laborpangs on the cross, he births us into new life; As she says, "He is our mother in nature, in our substantial making" and "He is our mother by mercy in sensuality, by taking flesh." Christ also cares for us tenderly, so "He is our mother in nature, by the working of grace." And she is, I think, undeniably right on all accounts.
* Mary Astell. A Serious Proposal to the Ladies, Part II is an excellent little manual on critical thinking. I've only read bits of The Christian Religion, which, alas, is difficult to find, but it's quite good as well.
* G. E. M. Anscombe. Her best-known work is probably Intention, but I prefer some of the articles in her collected papers.