I have found these sites useful in my research and teaching:
Buddhism & Asia
International Dunhuang Project
Primary Texts
Asian Classics Input Project (ACIP)
GRETIL – Göttingen Register of Electronic Texts in Indian Languages
Buddhist Digital Resource Center (BDRC)
Topical Sites
Art & Visual Culture
Museums & Collections
Western Himalayan Archive Vienna
Homepage of Christian Luczanits
The Metropolitan Museum of Art