There is also the option of excluding certain types of files, such as hidden files/folders, system files/folders, or specific file type extensions. You can also make a variety of 'data or application' backups, based on folders (everything under My Documents, for example), file types (all pictures, videos, music and such) or backup your email (including folders, attachments, and address book), and lots more. You can also make a backup of 'system state only', which copies the system files, folders, drivers and such, without copying your data.

You can make an 'image backup', which is essentially a copy of your disk or partitions of your disk, that you can later use to recreate an exact copy of that drive or partition. The latest version of Acronis True Image has a number of interesting variations on what 'backup' means. It has saved me, and several of my friends, from disaster a number of times over the years. I've been using their products for quite a few years - at least since True Image version 5 or so. Acronis has been in the backup business for a long time - pretty much as long as I can remember being interested in backing up PCs.

Acronis home edition