LiveUSB Install is a free, portable app to download Linux distros, save to disk as an ISO or even burn as a bootable CD, DVD, or thumb drive.
The interface sports a weird textured gray background reminiscent of Windows 95 desktop backgrounds. We don't know why, but we find it distracting. That said, it's relatively simple to use. Choose a mode including Distribution and four other methods that aren't explained.
There's an extensive list of distros, but it lacks any way of helping you find what you need. There's no way to scroll, alphabetical list, search, or anything to simplify your decision.
LiveUSB Install has many Linux distros choices, and you can save or burn your images any way you like. What it lacks is any way to simplify the process of picking a Linux distro, the one thing that's always held Linux back. We'd like to see the list be searchable and levels of skill required to install and use.