Which map API is the most powerful?
bing-maps, google-maps, maps
Solution
Think about which map is more suitable for you, have all the places you need. In US and Europe Google, Bing, Yahoo have pretty similar maps. However if you need other countries (in Asia, South America, Eastern Europe, Africa), the only answer is OpenStreetMap.
About API. The most powerful and flexible is OpenLayers, it allows you to connect to different map services. However it is a bit slow and complicated. In opposite Google API is fast and small, however it is bound to Google Maps.
If you are looking for some API contacting OpenStreetMap data, try Cloudmade.
Still choose the map first, and then select the most natural API for it.
Problem
Which JavaScript map API do you folks think is the most powerful? Google? Bing?