Grand Theft Auto IV - Custom Street View
I think this might just be one of the most awesome things I've seen ever. This Google Map lets you explore the whole of Liberty City, from Grand Theft Auto IV, in Street View.
GTA4.net have created custom Street Views of the whole of Liberty City and added them to this Google Map. The map shows all the important locations in the game, such as health & weapon pick-up points and all the important mission starting points.
However, once you enter Street View, you will forget about all that and just spend all your time wandering the streets of Liberty City through the amazing custom Street Views of the game.
The Street View option in this Liberty City map works just as it does on Google Maps. Drop the pegman icon anywhere on the map and you can start exploring the game in Street View. You can click on the arrows to navigate around the city and you can use the mini inset map to keep track of your position in the city.
I can't begin to think how many hours went into capturing the imagery for these custom Street Views and then lovingly mapping it all with the Google Maps API. Just ... wow!