In the settings, you can not only download maps for all the US states and countries all over the world, but also choose from more than 30 different voices in Spanish, English, Bengali, Italian, etc.
Some other interesting features let you select a 3D building view, get notifications about speed limits for different locations, and even avoid speed traps (in some countries). Though this application is, by default, set up for travel by car, you can also use it on foot.
GPS Navigation BE-ON-ROAD is a comprehensive navigation application. With it, you can take advantage of your GPS on your Android even when you're not connected to the Internet.
Requires Android 2.1 or higher