Whatever you do, don't use hotfile to keep backup. They leak their files to search engines which means there's a good chance your files will get reported and deleted even if you don't post them anywhere.

Rapidshare can change their policies at the drop of a hat. They also don't have a good reputation at storing files for any length of time.

x7.to and all such similar brands are scam. Don't use them. They provide no data security.

Megaupload offers a decent service for backing up your files but mind you all file hosters emphasize that their service isn't meant to be used as cloud backup and as such aren't liable if files are lost.

If its critical from your point of you view that you must never lose your files, use a cloud backup service like ADrive. They keep backups of all your files and never delete them.