Interactive Google maps on a C# winform

Almost missed the part where you said you're willing to replace the web version with something else.

Have a look at Great Maps - for Windows Forms and WPF. It is a custom WinForms control you can drop on a form.

It supports a lot of map providers, Google Maps included. They have a demo with which you can play and see how it works and how it can be integrated.

From experience, I can say that it is possible (quite easily) to bind to map events (marker clicked, double clicked as well).

Something worth noting is that using Google Maps with it might violate Google's terms of use (you also get a warning in the demo app). You can always explore some of the free providers, like OpenStreetMap.