I use Norton Ghost 2003 (for DOS, of all things) for doing image backups of my partitions and drives either once a month, or just before installing some new software, either for a review or if I think there's any chance of something going south.
Drop-dead reliable and fast - less than 20 min for a whole drive clone, and when I restore, less than 10 minutes. SATA and ESATA really make it fast these days.
I am starting to use a free Linux distro for this work called Clonezilla. Its interface isn't as slick, being all text based, but it is just as fast and (so far) just as reliable. On the bonus side, it works with more hardware than Ghost and it works better for LAN backups. Just burn a CD, or make a bootable thumbdrive, and you're good to go with it.
Acronis is a solid product too, but you're really just paying for a slick interface. You'll master any interface after working with any of these programs a couple of times...
-Llama