The Garmin nüvi 2597LMT is a comprehensive sat nav with free lifetime map updates and free traffic alerts. The excellent voice-activated navigation function is a real bonus too. Although it's still short of a few options, this GPS is a safe bet that earns a well-deserved five-star review.
Best of the rest
Garmin Zümo 350LM
Our friends over at Les Numériques gave this motorbike sat nav four out of five stars. The Garmin Zumo 340LM is a comprehensive and well-designed sat nav that's a top choice for two-wheelers. It has Bluetooth, a bright 4.3" screen, good route guidance functions and lifetime maps. It's just a shame that there are no connected services onboard.
On A Shoestring
TomTom Via 130
The TomTom Via 130 may not be the most recent model, but it offers a great range of functions at a reduced price. Build quality is good and the voice-recognition mode works well. Note, however, that it misses out on traffic info and on TomTom's more advanced functions. Pick the TomTom Via 130M to get lifetime map updates thrown in free.
Free Mobile App
Waze Social GPS App
This community based mapping, traffic & navigation app offers accurate information for users on the move with the added reassurance of community-sourced road and traffic updates. It doesn't have all the functions you'll find in paid-for navigation apps (e.g. route planning is still quite basic) but it's still a very good route guidance solution. Take a look for yourself—it's free to download.