The J-Link line of JTAG programmers from Segger is well known for their top of the line debuggers. The J-Link EDU Mini is a great option for those getting started with JTAG/SWD programming and debugging. Each J-Link EDU Mini is a version of the J-Link EDU Base in a reduced form factor with identical functionality for Cortex-M based targets. It has been designed to allow students and educational facilities as well as hobbyists access to top of the line debug probe technology.
With a microB USB port on one end, and a 2x5 SWD connector on the other end, just plug in the included cable and connect to your favorite ARM board to get started.