I wear Lake Pajamas more nights than not. They’re the most comfortable pajamas I have in my nightstand. I will fully admit that they’re not the chicest pajamas out there, but if you’re going for cute and comfortable… you can’t go wrong with Lake.
They’re having a huge summer sale currently so now is the time to shop (or stock up). For sizing, I think you can either go with your true pajama size or a size up if you want extra comfy or longer shorts/pants/sleeves. I have both XS and Smalls and like both. They do shrink slightly over time after lots of washes so keep that in mind.