I have used many free defrags and while some are better than others I have been faithful to O&O Defrag Free. Why? I read a review some time ago where basically all that are mentioned here where but through the test and bench marked and the one that clearly came on top was O&O Defrag Free. If I remember correctly, a close second was Auslogics Disk Defrag so I use O&O Defrag Free based on that review. All that are mention here are all good at what they do. I think it's more of a "love story" that most of use develop with the software and I'm sure that you would all agree with me.