I have been trying several newsreaders for the Usenet until I finally found the one and only newsreader Newsbin. I purchased it years ago and can only recommend it to everyone else who is serious about the Usenet. I do know however that some users prefer free software and that is why I took a look at the Pan newsreader which is available for Windows, Mac and Unix.
Pan Newsreader is offering a lot of features that commercial Usenet readers such as Newsbin are offering as well. It does support download binaries of course offering single-click encoding, multiple connections and simultaneous downloads and image previews of downloaded images.