Please!
Tights that fall down are the absolute bane of my life. I wear 40 or 80d opaque most days and just want to find a pair that doesn't require hoiking up every 15 minutes.
They also need to have enough depth in the top bit so that they don't chop me in half.
I don't wash my tights with fabric conditioner btw, as I know this can make them fall down.