I've cloned/imaged a few thousand systems (10k+) at this point, and my answer comes in two forms.
Clonezilla Live + FOG
Clonezilla Live is brilliant. It can boot from a CD or USB flash drive, mount shares via Samba, NFS, SSH, etc to save/read the images, and is all around pretty bomb proof. The user interface isn't the prettiest, but I prefer functionality over looks so it hardly bothers me. If I'm doing just a few single images, Clonezilla Live is as good as you can get.
FOG is for mass deployment. FOG is entirely based on Linux and can mass image Linux and Windows systems. I started using FOG years ago when nobody heard of it. Now it sounds like it's becoming the standard imaging tool for school districts and large organizations. FOG comes with a nice web interface to manage your hosts, groups, images, etc. It has a lot of additional features, such as wake on LAN, remote virus scan via ClamAV, remote disk wipe, scheduled tasks, multicasting, and more. It's pretty much the definition of awesome.
FOG is really meant for mass deployments, and as a result requires a server. Now this 'server' can really be anything with adequate specs (i.e. a gigabit ethernet port). I typically run FOG on an Ubuntu laptop, that way it gives me a mobile imaging device. If you're in an environment where your links between buildings is sweet (or if you're in one building on a single LAN) then a stand-alone server is probably more up your alley.
I don't utilize FOG as a backup procedure. I'm sure it could work, but Clonezilla Live just feels more fitting for backing up an entire image for backup/archive purposes. I treat FOG as more of a "oh gosh I have to get 1,000 systems imaged in a few days time, no personal data in the mix, what to do, what to do."
As a result, I have a hard time siding with one. I prefer both, just for different reasons.
I've used Norton Ghost, but it's kind of meh. I've had some issues with it in prior releases and admittedly haven't used it in recent times (mostly because with the above options, there's no reason to). I've also used Microsoft's WDS for mass imaging Windows 8 systems, but holy freakin wow, that software is terrible. It butchered some of our partitions despite reading the same answer file and expanded some, but not others. We're still cleaning up that mess.
There is another known as RedoBackup, which is more like Clonezilla Live with a prettier interface. It did the job when I tested it last month, but I wasn't too thrilled with the fact its last major update was 2012, while Clonezilla Live is pumping out updates all the time. Clonezilla Live's most recent update was (at the time of this post) within the last 2 weeks. FOG's most recent update was a matter of about 5 days ago. That, to me, is awesome.
