The Arduino Nano has been a favorite among people who do lot of work using breadboard. The nano can technically do everything that the Uno can do, in a breadboard friendly package. Insert it in a breadboard, plug in the USB cable and you have the most flexible arduino development setup.
Operating Voltage (logic level) 5 V
Digital I/O Pins 14 (of which 6 provide PWM output)
DC Current per I/O Pin 40 mA