I have a Garmin Nuvi 350 and like it a lot. I've used it on the east coast, Poland, and Italy. It even works on an airplane if you have a window seat facing the equator. I always recommend a Garmin unit over anything else. The Nuvi 350 is old and replaced with the Nuvi 260 now. The widescreen models don't give you that much more since they only show the sides.
I like the Garmin units because they have maps for everything. Garmins routing are great since they use Navteq. Tom Tom use Tela Atlas which are not as good in the USA. Googe Maps and mapquest use the same Navteq maps.