I have a Garmin, and I love it (with the exception of driving in downtown Chicago, where the signals are all screwed up by the tall buildings, but since that's something I don't do often, I can tolerate it).
I'd previously tried a Magellan and a TomTom, but I sent both of them back (thank goodness for QVC return policies!) because I didn't like them.
I do highly recommend, though, changing the voice setting from the American English (who has a really snotty way of saying "recalculating," as if she's letting out a big sigh and rolling her eyes, saying "I TOLD you to go right, you idiot, WHY don't you ever listen to me?!") to the British English (very servile and polite: actually makes driving more pleasant).
(Unfortunately for me, all the French voice options sound too robotic and overenunciate).