Ok need to ask who uses online maps what site has the best maps. I have check out googles, yahoo and mapquest all of them are not up to date so who has the best maps do you thing.
I know that our prime contractor uses a purchased google earth maps software, not sure on how updated the maps are, but they use it to measure properties.
Google Maps shows the house view. YellowPages.com Shows a very nice aerial image. I use multiple ones including msn live. It may be different in your area. It depends if the images are updated in your area for that site.
like Matt I use a combination of them all... each of them has different features that serve a purpose... if I had to choose a favorite it would be msn maps.
I like google earth for the measurement tool... property appraiser sites are also good for property details and with residential usually have a picture of the property from the roadside.
on a sidenote, I bought microsoft streets and trips for the route planning feature - while it is good, there are many areas where I work that have not been mapped in the software, and apparently they don't offer any software updates with regard to maps... NOT GOOD!!