Excel is by far still the most powerful. A lot of the hosted versions are just less powerful/sophisticated and slower.
You should also check out EditGrid. They have some great ways to pull external data feeds, and you are able to manipulate data much better.
Thus, it just depends how much data you are parsing and the use case. If you are using it for basic financial models without macros, Google is fine. However, once you start working with large data sets , macros, or more sophisticated models, Excel is still the best.
