I have a TomTom One which has terrible maps.
I also have a Magellan Roadmate 1200 which is the worst device I have ever owned, but I got it for free. If you want to read my review of it follow this link:
http://www.hondasuv.com/members/showthread.php?t=38371
I like my TomTom much better, but I would buy a Garmin over it in a heartbeat.