I've found CoPilot to be pretty good, having used it exclusively for a year or two. I tested pretty much all of them before I purchased.

If you don't want to spend (and you'll be in signal all the time), Google's navigation will do the job.

I use bog standard Google navigation, I assume there's better/fancier but it does everything I need.

navfree - download the maps and you won't need a live data feed

I'm sure the maps aren't perfect but they're easily good enough for me

+1 for Navfree

+1 for Google maps - can't see why you would need to buy a different one for most sat nav needs

+1 Google maps navigation thingy. You can even download map areas if you think that you won't be able to get a data signal.

google maps here as well. Does the job.

+1 Google Navigation. Live traffic. Use it even alongside the sat nav with built in TMC data in my car because Google Traffic seems to be better.

navfree as well .

Google Maps in the UK, but wont start nav out of signal which was never a problem as that was so infrequent. Now in Oz it's more of a problem tried Route 66 which seemed fine but wants paid now.