Best Sector by Sector Imaging Software

What is the best imaging software, not like Norton Ghost, that does a sector by sector image copy that does not affect the original drive? I have a failed RAID 5 drive and need to do a manual data copy on that drive (it has a couple of bad sectors, but no hardware failure to my knowledge) and want to make a mirror of it to a healthy drive and then try rebuilding my RAID again. Thanks.

Use dd from Unix/Linux/*BSD?