InfoWorld has an interesting
survey of data recovery & forensic tools. You need to register as an "Insider" to read the full article, which is well worthwhile, but here is the author's summary:
Which recovery tool is for you? PhotoRec and companion TestDisk have
consistently been among the most useful, performant, flexible, and
inexpensive applications available for data recovery. They don’t have
the breadth of options of some of the other apps examined here, but it’s
almost impossible to go wrong with them as a first step.
Sleuth Kit/Autopsy is more of a full toolbox than a single wrench or
hammer, and for that reason might be intimidating to work with,
especially if all you need to do is recover a particular file. But for
those who need the full toolbox, it is a great way to have one for no
initial cost. SystemRescueCd also rolls up a great many tools into one
bundle, but it’s strictly for experts. Those afraid of the command line
shouldn’t even think of using it.
Kroll Ontrack EasyRecovery Enterprise stands out with its RAID recovery
function, and it’s recommended for those who need that capability. For
those who don't, many of its other features can be found in other
programs, like Remo Recover.
Remo Recover stood out for making it easy to save out image files from
media, and for having some fairly exotic camera file types as part of
its database. CardRecovery supported a number of those file types as
well, although its slow scanning and slightly clumsy interface worked
against it.
Finally, Recuva packs a lot of great features into one program: fast
scanning, a convenient interface, and useful details about what’s
recoverable and what’s not. It should be in every Windows user's
toolboxThe main takeaway is that the best tools for most users are the free ones:
PhotoRec,
Sleuth Kit/Autopsy,
Recuva and
System Recovery CD.