TransitFeeds.com is a comprehensive directory of open public transit data, allowing users to browse and discover feeds from all around the world.
As of today (December 31, 2013), I've removed all subscription fees, making all areas of the site free for all logged-in users. Users can log in using their GitHub account.
If you're a user of public transit data (such as GTFS and GTFS-RealTime feeds), check out http://transitfeeds.com now!
Quentin Zervaas TransitFeeds.com founder