I'm partial to Windhorse books, but to be honest I haven't read many Windhorse books this year. Noble Friendship came out in 2004, as well as Living With Kindness, and Through Buddhist Eyes. Certainly last year was a banner year with Vishvapani's book on the Buddha, and On Reflection, which is the first Buddhist book I've read on reflection as a spiritual practice, instead of just reading someone's spiritual reflections.
Among the books that came out in 2012, I did enjoy Living Fully by Shyalpa Tenzin Rinpoche, and Patience by Allan Lokos. Both solid first books from different traditions. I give Shyalpa Tenzin Rinpoche best first buddhist book award for 2012. I looked at Lokos' pervious book and it's a daily meditations kind of thing, which is a buddhist book. In The Shadow of the Buddha by Matteo Pistono was a an important contribution to Tibetan culture and politics.