OpenStreetMap has such a level of detail (at least in Europe) that I can completely relay on it for my trips.
I went on a drive from Italy to Holland a month ago using MapFactor Navigatior with OpenStreetMap maps, and I was really surprised how good it worked. It even had POIs for the toilets on the highway! Amsterdam was mapped really well as well, with house numbers and everything.
And it was completely offline (even the routing algorithm) and free.