Does anyone know what's or what are the best cloud services out there? They got to be located somewhere in USA, UK, or Canada.
+1You cannot generally say what the best cloud service is.
If you want to save your files on a high security level use WUALA, CH.
If you want high performance, perfect usability and support from most of the apps connecting to cloud storages use Dropbox.
If you have much time use the free 25 GB of Microsoft's SkyDrive with a really poor performance.
If you need more than the offered free space of Dropbox look at this table.
I investigated all these informations for my blog.
You can also see which provider offers WebDAV supported by several apps for iOS devices including Apple's iWork suite.