We have been using Dropbox, JustCloud and SugarSync to cater all our storage and online backup needs. These are good in free and as well as in paid versions. Crashplan is good but it is limited to backup only and most of the companies and people prefer to use such kind of a service that can give them both backup and storage selections to upload and share their data onto the cloud network.
Apart from the aforesaid cloud vendors, you can google several others, or, can check the source link to find some more alternatives in the domain of online backup services.