There are many mapping solutions available that you can use, but the big problem that you have isn't actually the mapping software, it's the map source data. This is where the licensing actually comes into play because you usually have to source the map data from somewhere, and even Google maps have to purchase this mapping from somewhere - they then pass the cost of the license on to you. If you aren't too worried about 100% coverage, you might want to take a look at the OpenStreetMap project which is an open source project aiming to provide geographic data.
Anyway, if you want free software and you are using .NET, you can always download SharpMap. For an online solution, you could look into DeepEarth.
Alternatively, if you are looking to pay for a commercial solution, you might want to look into ESRI or MapInfo solutions.