Recommendation for a Easy to use and reliable Duplicate File remover

If it's an application you're looking for, I've bought several - Singlemizer (which I look for the preview window), Araxis Duplicate Files (which I like but get annoyed because I have to re-up every year) - and I've tried a few others.  The big mistake I made in the past was to delete what turned out to be the masters in Aperture and kept the previews.  BIG mistake.