YCbCr or RGB

[Automission]

So I've had my tv set up for a while. Now I'm still unsure on these settings, which to pick. I find with RGB on a DVD the colours look true, and correct. With YCbCr it all looks washed out, blacks look grey.
I've heard people say they should look identical if your TV is calibrated correctly, but that's gotta be bull, otherwise why bother picking one, they'd both look the same quality.

So I'm currently on RGB for DVD's, but I'm hearing YCbCr is better for Blu Rays, which I've yet to test. But is this true, or again will it just wash out the colours? I don't really want to keep changing them every time I change from a DVD to a Blu Ray.
Stuff like that irritates me, I don't want to sit down to watch a film, only to remember I've got to recalibrate the TV and change all the settings before hand.