SpinRite, from GRC, is a very low-level hard drive maintenance and recovery tool. It isn't free ($89 for first-time purchases), and it is not terribly pretty, but is very advanced. The UI (and their website) needs some design help, but they have the tech side of things down.
![alt text](https://cdn.statically.io/img/i.sstatic.net/FwLUd.gif)
DFSee (€49) is not for the neophyte but looks comprehensive (i've never used it). DFSee is a generic disk, partition and filesystem utility for maintenance and data-recovery.
![alt text](https://cdn.statically.io/img/i.sstatic.net/YqgTN.gif)
Hard Drive Mechanic is another commercial, but slightly less-expensive ($69), product option.
![alt text](https://cdn.statically.io/img/i.sstatic.net/7xx2c.gif)
Other choices include SeaTools from Seagate and Western Digital's Data Lifeguard.