There are many reasons why people love "Blue Bloods." First and foremost, the show has a strong commitment to depicting a loving family in the form of the Reagans, most of whom are involved in New York law enforcement to some capacity. It follows this up with amazing accuracy regarding police procedure, which should come as no surprise seeing how the series has a New York City police officer serving as a consultant (via CBS 58). As such, the series has managed to maintain audiences' interest for well over a decade.
With that being said, the show isn't exactly known for being the funniest thing around. There often isn't a lot of humor to be mined out of the types of cases the Reagans find themselves in. Still, the family manages to crack a smile every now and then, which has led to some surprisingly funny moments, including one standout moment from Season 1.
On the surface, Season 1's "Officer Down" doesn't exactly come off as a barrel of laughs. The main plotline follows the NYPD getting involved after a fellow officer's death during the line of duty during a jewelry store heist. However, between all of that, we get a scene of Jamie Reagan (Will Estes) out on patrol with Sergeant Renzulli (Nicholas Turturro). They come across a woman shaming her cheating husband by holding a sign calling him a pig. To really complete the message, she has an inflatable pig by her side. The officers tell her she has to lose the bullhorn and the balloon-pig, which seems like the end.
However, at the end of the episode, she returns to add some much-needed levity to an episode that needs it. Jamie and Renzulli return to the same block to find the woman once again trashing her husband, only this time, she's gotten an actual pig to stand by her side. The officers are more impressed with the display than anything and decide to leave her be. It's humorous in part thanks to how unexpected it is after a relatively dark episode, and much like the two officers needed a bit of a laugh at the time, the audience also benefits from not having everything being so dark and dour all of the time.