All of the imaging software mentioned is good for some purposes but not for all !
Acronis : general purpose imaging for intact systems. Not one of the fastest when used from the bootable CD. Has BIG problems with systems slightly corrupt or presenting defective clusters (will simply error out). Images have to be verified to be sure that you have a useable image, and even then it happens that Acronis errors out at reinstall. Has a nice feature called Universal Install for bare metal reinstalls, but this works only on unformatted, unpartitioned hard drives.
New versions generally have massive bugs, so do not use in production or repair. Western Digital and Seagate have free branded clones available on their website.
Ghost : the big classic. Versions 8 and 11.5 are the ones mainly used in repair as these two versions are extremely stable and can be configured for imaging on slightly corrupted drives. No bare metal installs possible, often complications with Ghost wanting to write to disk before imaging.
R-Image : not very reliable in my experience, has big problems with corrupt drives. Doesn't error out frequently, so you don't know if your image is ok or not. Nice function to mount images as virtual drives, but doesn't mount corrupt images like Driveimage does.
Driveimage XML : IMHO by far the fastest imaging software available. Has sometimes some difficulty reinstalling images, but unbeaten from bootable medium. The images, even corrupt, can usually be mounted for file retrieval.
No bare metal install. Free version available.
SpeedClone : ingenius DOS cloning tool (bit by bit) can clone stuff no other Windows software can even touch. Takes LONG, needs to repair MFT after cloning, so not something for the faint hearted. Runs from floppy only, limited use on SATA drives.
HD Clone : Nice and fast, has trouble with corrupt hard drives. Updated frequently (minor updates and bug fixes)
Paragon : used to be "forget it" but the recent versions are quite nice. Backup is still a little slow when run from bootable media, but appears to work ok on corrupted media (IMHO better than Acronis). Very complete, bare metal restore possible, but I haven't used this for long enough to be able to say reliably.
Active@ Disk image : straight disk cloning and imaging, not many special functions but does its job. Good (maybe best) bootable media, works with all windows systems I have worked on (which can't be said about many others where SATA recognition is an issue). No bare metal.
Farstone : version 5 was the first useable version, version 7 is nice. Can image stuff the others can't, so if you have trouble withother cloning software, give Farstone a run. Comes bundled with lots of hardware, eg Samsung DVD writers. I don't like to keep this installed on my work computer, as I find that it slows down seriously, but ok on imaging computer.
Macrium : Good, but has some issues reinstalling from backup media. Network recognition is not very good, so I had several not so nice experiences when trying to reinstall from NAS. Very nice bootable media, Linx, Bart PE and WinRE editions of bootable media can be created. Runs without difficulty on Windows machines and barely slows down the use while backing up. Shadow and VSS modes are possible. Has a unique boot repair function that does work once in a while. Can be used on server (2003 & 2008) but not on SBS in my experience.
CloneZilla : If you know how to use, the absolute best. Need PhD or several years at NASA to fully understand the VAAAAST possibilities this software offers. Nothing is impossible, if you can load the drive you can clone it.
Partimage : great software, unbeatable for networked imaging to Samba
Waxar : The secret weapon of imaging. Takes some time to get used to, german editor, but does incredible stuff when you know how to use and especially how to configure.