Your best choice is probably the Radio Shack 15-2104 that is being closed out in the stores for ~$10. It can do many discrete codes out of the box. It is JP1 compatible and with a JP1 cable you can do just about any command.
Start with
www.hifi-remote.com for more information.
It will also help if you describe your equipment since we may already know if what you are looking for exists. For example, any Toshiba TV other than recent rear projection systems do not have any discrete commands available. In contrast, almost every Sony device does.
-Jon