I probably use Google now more than ever...mostly due to Android. Aside from that, I don't think any of the competitors come close to gmail or maps. The main benefit of gmail isn't the storage space (anymore) ,but the fact that it has much more advanced tracking, organizing, and search options over the competitors. Nothing else really touches it in that category and I know a lot of other people forward their work emails to it as well in order to have everything more organized/searchable. Also, docs integration can be pretty huge, surprisingly.
And maps....well, all the companies have always used the same Navtech info, but google maps has the userbase, and thu usually the most accurate info on businesses/etc.