LM7805

This is a very popular linear voltage regulator used everywhere. The only catch is that a lot of heat sinking is required if you have a large current load and a large delta between VIN and VOUT

Specs: http://www.fairchildsemi.com/ds/LM/LM7805.pdf

Voltage In: 5V-18V

Standard Voltages Out: 5*, 6, 8, 9, 10, 12, 15, 18, 24

Current Out: 1A

Highlights:

Schematic

Package comes in TO-220-3