General and introductory

Cultivating a Daily Meditation - His Holiness the Dalai Lama
The Art of Happiness - HHDL
Wisdom Energy - Lama Yeshe and Lama Zopa Rinpoche
How to Meditate - Kathleen McDonald
Introduction to Tibetan Buddhism - John Powers
Tibetan Buddhism from the Ground Up - Alan Wallace
The Boy Lama - Vicki Mackenzie
Reborn in the West - Vicki Mackenzie
Being Nobody, Going Nowhere - Ayya Khema
Mindfulness in Plain English - Venerable Gunaratana
Cutting through Spiritual Materialism - Chogyam Trungpa Rinpoche
Rebirth and the Western Buddhist - Martin Wilson
Tibetan Book of Living and Dying - Sogyal Rinpoche
A Path with Heart - Jack Kornfield
The Experience of Insight - Joseph Goldstein
Being Peace - Thich Nhat Hanh
Open Heart, Clear Mind - Thubten Chodren

Intermediate

The World of Tibetan Buddhism - His Holiness the Dalai Lama
Healing Anger - HHDL
The Good Heart - HHDL
Sleeping Dreaming and Dying - HHDL
Introduction to Tantra - Lama Yeshe
The Door to Satisfaction - Lama Zopa Rinpoche
Transforming Problems - Lama Zopa Rinpoche
The Door of Liberation - Geshe Wangyal
The Tantric Distinction - Jeffrey Hopkins
The Tibetan Tradition of Mental Development - Geshe Dhargey
The Four Noble Truths - Geshe Lobsang Gyatso
The Harmony of Dependent Arising and Emptiness - Geshe Lobsang Gyatso

Advanced

Kindness, Clarity and Insight - His Holiness the Dalai Lama
The Dalai Lama at Harvard - HHDL
Liberation in the Palm of Your Hand - Pabongkha Rinpoche
Meditations on the Path to Enlightenment - Geshe Thubten Loden
Path to Enlightenment - Geshe Thubten Loden
Mind in Tibetan Buddhism - Lati Rinpoche
Death, Intermediate State and Rebirth in Tibetan Buddhism - Lati Rinpoche
Meditation on Emptiness - Jeffrey Hopkins
Emptiness Yoga - Jeffrey Hopkins
Tantra in Tibet - His Holiness the Dalai Lama and Jeffrey Hopkins
Highest Yoga Tantra - Daniel Corzot
Overview of Buddhist Tantra - Panchen Sonam Drakpa