Blue Bloods is a great option and has a strong emphasis on family, respect, loyalty, etc. It is about an Irish Catholic cop family in New York. Tom Selleck is the Police Commissioner and the rest of the family is all involved in either police work or prosecuting. It is very atypical of most crime shows. There is no glorifying of criminals, nothing gruesome, and it focuses more on the family being supportive of each other than it does the actual crimes.
And since it is such a large, multi-generational family all sticking together there are characters of a wide age range that can connect with a wide variety of viewers.
Though I suppose the age-range of the young people that would be watching it with you would also matter. Someone in early middle school might find it boring.
Edit: As well as content. I know little about children and what they watch, so a show featuring police officers may seem remarkably clean and nonviolent to me but not be the case for kids.