NASA Worldwind has been around for a while, and there used to be a dodgy plug-in for it that allowed you to use the Google Earth data set. That gave you the best of both worlds (ha ha! - I made a sort of pun).
The quality of the Google satellite imagery certainly used to be better for the UK than NASA Worldwind. I've not checked recently.
For our area (west Wales) the winner is certainly Windows Live Local (a web site), because it has the highest resolution satellite imagery.
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