My favorite software is iGO-Primo.
Good route calculation algorithm, beautiful graphics and great customization.
I started using iGO8.3 in the year 2008 (on WinCe 5 devices).

For testing (for users of the Italians forum), now I have these softwares on the Android Tablet:

Sygic = Latest versions (15.xx) are very bad (also bad the route calculation algorithm).

Tomtom = The best route calculation algorithm.

CoPilot = Good route calculation algorithm.

Navigon = Good route calculation algorithm.

Obviously this is what I have checked......of course each one may have different opinions