I too find it difficult to choose a single most important book. Having enjoyed and practiced photography for many years, I feel that my technique is mature and satisfactory. And I do have many books to thank for their guidance and knowlege over the years. Today, my library is more for inspiration and motivation than for finding a personal style. And to list a couple of favorites would be to omit other equally worthy volumes. (Ask me again next week, any I'll supply a different list.) Anyway, here are some recently acquired Hypno-Tomes:
1. Adam Bartos: Kosmos, A Portrait of the Russian Space Age
2. Ben Maddow: Faces
3. Das Atelier des Photographen, 1912