Probably the best introduction book to existentialism I have read.
The author made excellent choices for the books structure - Husserl, Heidegger, Sartre, Merleau-Ponty, De Beauvoir, and the legacy of existentialism in France. You'll notice this is more Francocentric than other introductions, like the VSI, which suited my interests perfectly but might not be what everyone wants. Dedicating a chapter to de Beauvoir is very welcome too, considering her contribution to existentialism, in particular, is often overlooked.