Yahoo maps (maps.yahoo.com) is officially on top for me -- even though I don't like the interface any where near as much as Bing maps or even Google maps which is a distant second.
This weekend we're traveling from our address in Georgia to an address in Alabama. Our subdivision is about six years old and to this point no one has been able to get directions from a mapping site. In fact, Bing Maps and Google Maps still don't know about us. Our destination is in a similar circumstance.
I was surprised when I tried Yahoo maps today. Our address was there, and our destination was another address on the same road. Very nice. Bing Maps got us from zip code to zip code which is helpful, but not enough so. Google maps wouldn't even approximate to the zipcode. Instead it asked me if I meant some other place in Alabama with a completely different zip code that had the city as part of the street name. Way off and completely useless!
Maybe Google and Microsoft need to concentrate on quality of content instead of glitz.