Recs.
Updated
SpecsUpdate
Pros
Pro Allows sharing a single file via link
Whether using the desktop client or web interface, simply right click on the file you want to share and select Dropbox > Share link, then send the link to the people you want to share the file with. The recipient does not require a Dropbox account.
Pro Easy to use
You can use Dropbox via website, by installing a desktop client that creates a folder that you simply drag and drop files into, or with their mobile app. Everything synchronizes across all devices used and cloud storage. Dropbox also offers easy methods of sharing whatever is within it.
Pro Accessibility/Availability
It's available on all platforms, Mobile (iOS/Android), Linux, Windows, MacOS and if none of those work, then you can access it from a browser.
Pro Sharing
Dropbox allows simple sharing of folders so that you can use it to easily collaborate. Even if in a development environment you can access the same code base and/or put subversion or other repositories in Dropbox. You can select the folders you want on any device (selective sync).