I like Bing for their Birdseye view. The resolution varies depending on the area, but here in RI I can zoom right in to individual boulders. Rotating it around the 4 angles also allows you to pick up on things you wouldn't necessarily see right away. Also, the different angles are taken at different times, so there is a chance you will get one or more from when the leaves are down.
I do use Google also though.