I very much enjoy the Garmin C330. Very easy to use and has great accuracy. Comes with all US maps preloaded, will work on its internal battery, has a suction cup for windshield mount, and you can set the voice that speaks the instructions to you to a variety of different languages. Also has a port to upload free map upgrades for the life of the unit.

It can be had for $570 on www.tvnav.com. Normal list price is $899.