Alrighty so I'm a graphics nut who likes to try to get the BEST picture out of anything and will spend hours on end tweaking stuff just to make it look pretty on my nice little Dynex 42" LCD. I've got my 360 rigged through HDMI, with the reference levels set to expanded, but when I go to tweak the color space, I don't really notice a difference unless I switch the reference levels back to standard, and even then, it only looks good when you set it to the YCbCr709 and YCbCr601 settings, so let me wrap up my babbling and get straight to the point.
Could someone please provide more detail of what this setting does (aside from restating the breif, somewhat vague, descriptions I can see when I'm setting it up), and give a recommendation on what would probably be best for providing a vivid, clear picture. I've got my Tv set to default settings, and all picture enhancements (or enhancement, seeing how there's only one) are turned off for the moment and I'll fiddle with that later.
QUICK VERSION: HDMI Color Space. What's the best. Make it pretty. Go.