* Portability
* Functionality
* Lack of OS support
* Speed
* Ease of use
My favourite after a year of trying is without doubt dropbox.
Why?
A.) The fact that sharing with other users is so easy greatly favours choosing dropbox It's also a fact that dropbox is the most commonly used online storage solution.
B.) Dropbox also supports a wide range of systems: Windows, Mac, Linux, iOS, Android and BlackBerry.
C.) You get 2GB storage for free. By doing some tasks and referring some friends you can easily get above 18GB of free online storage. If you want more, you can easily upgrade to hundreds of more GBs of storage.
D.) The seamless synching works absolutely flawless. You get a directory on your computer which automatically syncs to your dropbox account, and so to the rest of your devices. You can work directly against this directory without a hitch.
Give it a try!
