We shopped at all three last month and were happy with most of the choices at each. However, we did notice that Simply only had one brand of sunscreen and it was really expensive. We went there over Petite Casino thinking it would be cheaper, but once we got back to Orient, we realized it was a mistake. We even found cheaper options at the tourist shops in Marigot. So if you see reliable sunscreen for less than 14 euros (the Simply price), buy it if you think you'll need it.