Any recommendations for accurate scale?

Hello all...

We are serious about watching our weight but are frustrated by the
scales we've bought. It seems we can vary the displayed weight as much 2-5
pounds simply by shifting our weight or slightly moving our feet while
standing on it. Does anyone have a good recommendation for a scale, analog
or digital, that displays consistent measurement? Is there such a thing as a
"smart scale" that detects whether your body weight distribution on the
scale is proper for an accurate measurement? Or a scale that detects whether
it is not perfectly level (we have quarry tile in the bathroom)?

Thanks for any help you can offer.

Bob & Flo