UPDATED: We've updated our list with the best sat navs and our new top five sat nav app.
The car sat nav (GPS or navigation for Americans) is an essential form of technology that we all take for granted. These days, with GPS-supporting smartphones and apps from the likes of TomTom, Garmin and the rest, you don't necessarily need a hardware sat nav, but they are still coming out from a few stalwart brands. Specifically: TomTom and Garmin.
Long story short: hardware sat navs have better GPS receivers, which is particularly important in urban areas, and only really do one thing (although Garmin is always keen to bolt on fancy extras).
Smartphone sat nav apps have better interfaces and screens, and are cheap (if you ignore the cost of your phone). Some are even free.
Another peculiarity of sat navs is that because the core functionality has barely changed in a decade, they tend to remain on sale for years, at ever-reducing prices.
Anyway, if you want a sat nav that won't let you down, you've come to the right place. The top five hardware devices are on page 2, the top five apps on page 3, a couple of oddities – a HUD and a motorbike specialist – on page 4. You have now reached your destination, says "English Jane".