TomTom on a phone, easy-peasy. Of course, if you want to use it properly, it’s £19.99/year, but having used Navmii, Here, CoPilot, Google Maps and Apple’s Maps over the last year, driving something like 40-50,000 miles, TomTom is, without a doubt the easiest to use, the maps, routes and directions are much clearer, and the phone app is identical to the standalone unit, which my team leader uses, so I’ve been able to compare the two.
Advantage with the phone is you’re unlikely to leave your phone behind in the car and then have it stolen, or else have to carry two items around with you.
Combined with a BT headset for the occasional call the app gets live traffic updates like the standalone does, and which does work very well, a diversion off the M5 near Tewksbury on one trip took me from 11a to 10, and as I drove over the motorway I looked down directly at the car and caravan blocking the road, the satnav told me to turn off just as the matrix signs lit up showing an accident ahead.
If all you need is occasional usage, then some of the others would probably be perfectly OK, and they’re free, but TomTom is the best, no doubt.