What is the best way to backup your entire system?
What are you trying to backup?
If you are looking to backup your entire data on your system then I can recommend an online backup solution such as My Online Backup (http://www.my-online-backup.co.uk). This automates the backup process and securely stores these file online. It also allows you to to recover up to 30 versions of the same file from the web portal.
If you want to backup the entire system including system state then (and you are on a Windows machine) then you can use Windows Backup to do this. It is free and is included in all the versions of Windows in one form or another. The business versions of Windows allows you to make granular backups, where as the home version generally allows you to only backup the entire system or entire Documents folder
In a corporate environment I can recommend Backup Exec for backing up to tape or NAS. It is a proven technology that just works.
Hope this helps