I totally agree with you €dstowe - a backup is a necessity, not an option. If choosing what needs to be backed up is preventing anyone from performing a backup, don't let it. Whatever you choose to omit from your backup WILL BE what you need when disaster happens.
Take an image NOW using Norton Ghost, or a similar programme. Yes, it will be a waste of time; that is until you need your backup. Then it will be a complete Godsend.
That's enough preaching for now - Merry Christmas.