The STANDARD settings (rather than the default Dynamic) would be best for rooms that have some ambient light.

C|Net does have an HDTV Picture Settings Forum that people post their best or preferred setting in, and that can be found here:

Others have a professional calibration performed that takes other variables into account, such as room size, amount of light and other factors. If that's not something you want to do, you could probably start at Standard and adjust the settings to your taste.