Easiest, most *Reliable* BU method - disregarding cost ?

Personally, I used Macrium Reflect's Free Edition on my laptop before I upgraded from a 160gb drive to a 320gb. It imaged the original drive and I was able to restore easily on the new drive, exactly as I left it (except for having more space of course).

I was so pleased at how easy it was and non-time consuming, I now use it on all four PC's as my back-up program. You set up the parameters for what to back up (just your OS drive, certain partitions, all drives & partitions, etc) one time. Then, once you have this set-up, you add it to the scheduler. So, I have mine to run every Sunday morning at 2am. It backs up to an external drive.

Over time, I delete older ones as space diminishes, but I'll usually keep one REALLY old one in addition to the more recent copies.

If you don't want to do this, you could set-up a RAID5 array. This way if one drive goes bad, you can continue to use the system until you replace it (but if a second drive fails before you can replace the first one, then you're in trouble). Honestly, I don't think this is the route to go, because if for whatever reason you want to go back in time and restore the computer to how it was X days ago, this method won't help. However, it does offer the least amount of user input (you won't have to manage any image files, etc).

Hope this helps some / gives some additional options to consider...