I found a great quote on this subject this morning.

There are numerous sidetracks that lead to a distorted, ego-centered version of spirituality; we can deceive ourselves into thinking we are developing spiritually when instead we are strengthening our egocentricity through spiritual techniques. This fundamental distortion may be referred to as spiritual materialism.
-Chögyam Trungpa Rinpoche

Spiritual Materialism seems tailor-made for western Buddhism and 'American' Buddhism in particular.