Gita Supersite
http://www.gitasupersite.iitk.ac.in/index.htm
An all-inclusive site with translations in multiple languages, as well as text details, commentaries, and related links
International Gita Society
The International Gita Society collects information on Hinduism's spiritual practices in this umbrella site, which also includes commentaries on the Gita and several bibliographies.
The Battlefield of the Mind
http://www.atmajyoti.org/hi_gita_commentary_1.asp
An introductory commentary to the Gita, with applications of its teachings to daily life; good for the student looking for practical applications of its message, particularly in the context of meditation