Google Street View - With Street View you can explore the world at street level.
Google NightWalk - An audio Streetview tour around Marseille
GeoGuessr - GeoGuessr is a new way to explore the world in a gaming style.
Google Street View Oceans - "Street view" on oceans around the world
OpenStreetCam - OpenStreetCam that was also known as OpenStreetView, is a service dedicated to offering the real images of the most of the locations of the world.
Google Street Discovery - Discover 9,000+ beautiful Google street view locations