Dup Detector

I estimate that I have about 20,000 images not including HCG sets and manga scans, and I've noticed a lot of duplicates here and there.  Which duplicate detection program would you guys recommend?  Which one has the most and best features out of the bunch? 

The last time I used such a program over a year ago, I noticed that it didn't work so well with black and white images.  Are there any of these programs that do?

Jesus, do people ever read this fucking board before posting? This question has only been asked five times already this year, the last less than a month ago.

PS. DupDetector has the worst UI ever.