Borrowed a Garmin GPS one time, several years ago. It was programmed to say "Recalculating" in an annoyed voice whenever its driving directions weren"t followed to its satisfaction.
The "Recalculating" was funny the first time, and irritating by the third time. By the end of my trip, I swore I"d not buy a Garmin GPS unless it was the very last GPS in the whole world.
Since then, I"ve used a few different Tom-Tom models, which figuratively shrug their shoulders and carry on without mouthing off.
One other note: I"ve found that I prefer the units that don"t change the orientation of the display based on which direction they think is up/down at a given moment.