I used to use Ghost, but recent versions got bloated so I switched to Acronis TrueImage. It's very fast (300gb in under 2 hours), can backup both in Windows (while you're using the computer, no less) or from a bootable CD which runs a custom version of linux.
I haven't used the current version though. I bought version 8 a couple years ago and haven't bothered to upgrade since it works fine. I know they've added a bunch more features but the basic disk cloning is still there.