I like that hazel will automatically organize things for me based on some very simple parameters. It automatically files away my scanned documents, sorts them into folders by date. It keeps my desktop and "working" folders clean so that I don't have a constantly expanding load of files on in either place. Staying neat helps me to stay productive. I like its potential toward automation and how you can trick it into doing something based on the contents of a file - scan the file to see whether a certain phrase appears, and then give it an if / then "to do" item. Review collected by and hosted on G2.com.
There's a bit of a learning curve to really get into it, and in order to make that learning curve you almost have to seek out and pay for third party help from someone like MacSparky or AsianEfficiency or elsewhere. Otherwise, it's pretty great. Even if you don't do anything with it other than organizing your desktop or your "working" contents folder (or downloads folder, or anything like that), it's still useful and worth the price. Review collected by and hosted on G2.com.