Garmin
I have a Garmin (with lifetime updates) I got at Goodwill for $25. It seems to do fairly well, though SWMBO swears by her iPhone. Which ceases to work in less digital areas (yes, there are some here in the US), so I'm glad to have the Garmin as a backup.
The newer Garmins don't verbalise the "recalculating", they just show it on the screen. And it seems to catch on fairly quickly if I choose to go a way I know better, rather than the one it thinks I should use.For $25, I really can't complain (and if I did, it would do no good!)
I have also been led to a ferry, and have managed to correct a database error which led many to assume my address didn't exist (the road I live on has a section in the middle which is passable only by four wheel drive jeep or HMMWV, except for Spring, when the mud hole will swallow anyone who tries). House numbers start at one end and continue after the impassable section. Getting NAVTEQ, Google, Garmin, and the others to fix their databases took me almost 3 years of posting and reposting detailed corrections to their websites. They DO look at them, but very rarely.
// one question nobody has been able to answer: if you stop, roll down your window, and ask directions, what guarantee do you have that the bloke giving you directions knows any more than you do?