I think m&s "magic" black opaques are fab. Good high waist, really good at holding in a wobbly tummy and keeping bottom & thighs neat too! But I need the equivalent in navy (and would buy grey too if available). Looking for about 60d but even 30 or 40 would be fine. Don't mind paying a bit as they last for ages! Who else does amazing really slimming tights so I can look for colours?