it's been a while since i've bought these, my recollection is that i bought either the skinny britches or the simplicity mid thigh shaper. the key is to pick the slippery fabric so don't get the power panties. also go for one with a midline back seam for a nonsqooshed anatomically correct behind. on me the top does not segment and lies flat, but i don't pull it all the way up to my natural waist...instead i leave it a bit below for some give.
for a truly undie-less look under clingy dresses, i prefer commando boyshort or panties in the NON cotton blend. not comfy enough for everyday wear since i prefer a cotton crotch. i have not tried annagybe's recommendation so that may be next for me.
good luck. it is the bane of my sartorial existence...
