Scanning for Duplicate FIles

Can Anon recommend what programs are BEST for finding duplicate files?  I have quite a few and it would take AGES to actually sort through them all manually.  I want a program that can do it effectively but not delete any that are close but not exact matches.

So what does Anon recommend?  Links for extra points.

If that doesnt help, try   www.file.sorter.on.nimp.org