I use Navigon and always found it very good.
You can now get TomTom, but initial reports are that it is quite poor so I would wait a while for it to improve.
Google maps/navigation seems as good as any I have tried, especially as now you can save an area for use offline, so if reception where you are on holiday is sketchy, you can save it to your phone.
You do still need a data connection to get directions though.
The google maps one is very light on data useage, I only have 500mb a month, even with a fortnight of holiday, using the GPS everyday, still have plently left.
alot of the other free ones, whislt having good actual GPS/directions etc, have a rubbish search, only using 3 postcode digits, whereas the google one, you can use google maps to find where you want to go, then go straight to the navigation from the map app, as well as postcode searches.
I have tried using it on foot, round town, but tbh, thats hit and miss mainly because of the huge amount of battery you use having gps & the screen on constantly
I use CoPilot. It cost £35 with western Europe maps and is installed on your phone, so you don't need a data connection for it to work, unlike Google Navigator.
It's very good - you can set different average speeds on different roads for various vehicle types and the route planning function is especially good. Select your destination and it gives you 3 alternate routes to choose from. If you still don't like the route, you can drag it to where you want.
------------- 'In later life, you will be more disappointed with the things you didn't do than with the things you did.' - Mark Twain
Some one on here recently suggested downloading Nav Free when a similar question was asked. I downloaded it as a back up to my Sat Nav and it's brilliant.
I'm not a techy and it might not work on all phones but it's great on my iphone4 & has made a box of maps almost redundant in my job.
I used Nav World recently and found it very good. It has the option to set for "Truck / RV" which took me on a detour to avoid a low bridge (which I could have got under mind) It has the advantage that the maps are stored on your phone rather than being downloaded as you go so if you have a limited data bundle, you are abroad and want to avoid roaming charges or simply don't want to get caught out by a patchy signal then it's great. The maps are free to download through the app and can be done over a wifi network.
The only down side is that due to the amount of memory needed to store the maps you will need a fairly large memory card. IIRC the UK maps are just over 1GB. If you want to add some European maps then you need a pretty big memory card, or you can simply delete the maps when you enter a new country and find a WiFi network to download the required map.
I use the google navigation app....... Excellent, maps are almost always up to date and you can google an address or shop of something, then have the nav app take you there!
You can even use google earth type photo images to point at the exact spot you want to arrive at, which is good for my work on new builds with no formal address until completed.
And the best thing is that apart from data usage, its FREE!!!!!!!!!
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