JDownloads is amazing. It is a dream for you to customize. The developer uses tags in the layout, so you can practically design it any way you want from the backend. There are SO many options and configuration settings so you can make it do almost anything. The developer is always present, answering questions and more than willing to listen to your requests. He added a feature I really needed to the next release. All I had to do was ask! How is that for customer service! A+++
Did I mention it is free! I can't believe it, but it is, so if you use and like this extension, please donate to the project because they deserve it.