The Cisco C series support CEC on the hdmi outputs and I have tested this with Samsung, Sony and Sharp.
Just ensure you enable CEC under video outputs and it will automatically power on and off the TV. Also if you are using the Cisco touchscreen as well ensure you hard set the resolution on the codec to 1920 x 1080 at 60. Otherwise you get some minor issues with the menu changing from white to black modes.
I've had great results with Sansung and Sony.
Only annoying this is that C40, C60 don't have two HDMI outs but the SX20 and C20 does so you can do dual screen and it will turn on and off automatically. It's really a great option without delving into commercial screen models.