The NooElec NESDR Mini SDR & DVB-T USB Stick (Model R820T) is an amazing little USB Software Defined Radio device I picked up off of Amazon just a few weeks back. With this and some software, you are able to tune and listen to everything from air traffic control frequencies to your favorite radio station. (HF is possible, but you would need an upconverter). For the price, this is a definite buy if you are looking for a new, cheap hobby.
What comes with the R820T? You get an antenna and a remote, which I have found 0 uses for currently.
-Full compatibility with a large array of software packages, such as MATLAB®, HDSDR, SDR Touch, SDR#, Planeplotter
-Frequency capability of approximately 25MHz-1750MHz
-Female MCX on the USB Stick, Male MCX on the antenna. (You can buy adapters for other plugs such as SMA)
If you would like to purchase one of these, try either of these links.
For a video on how to install the software for the dongle, click here. https://www.youtube.com/watch?v=dyF7YRT4YTU