A recent study has revealed the happiest size is a C-cup. More women wearing this bra size reported they felt satisfied with their boobs when compared to other sizes. What size is it? 39 percent of women with a C-cup said they loved or liked their boobs out of five options including didn’t mind, disliked or hated their breasts. The next happiest size was a D and DD, with 37 percent of women saying they loved or liked their size, followed by 34 percent for A and AA.