I have a Garmin nvui 265WT (midrange model w/ wide screen and lifetime traffic) it's very easy and intuitive to use, and I really have only one minor complaint, the volume of the speaker could be louder when it calls out turns.
We had some additional discussion on the GPSes and how some are less user friendly than others here:
http://www.cigarasylum.com/vb/showthread.php?t=37025