The most heartbreaking ones I've seen are in schools, or anywhere that children are involved.
Not heartbreaking, but the ones that get my goat up most are flyers from craft fairs and worse places promising to teach crafts/arts. How is that not a sign to walk very quickly in the other direction? Or maybe it is intentional, like some bad spam text apparently being intentional to weed out the people who are less likely to fall from the scam anyway…