http://www.gamedevmap.com/index.php
Publishers, development studios with a staff of five or more, studios with previously published games, and studios under contract with a publisher are listed.
Gamedevmap is a growing database of video game companies. For the sake of general curiosity, you can spot at a glance the most prominent areas for video game developing -this is a little tricky though, since the spots don’t give visual information on the number of companies on each one of them-. However, I believe that this link will be most valuable for those interested in entering the business, since it saves countless headaches searching for the companies’ locations and sites. Beware that not every company is covered: the webmasters rely on the readers’ help to complete the list, so this could be your opportunity to add a spot! 🙂