For several years, we've been following Andrew Terraciano, who portrays Sean Reagan on Blue Bloods. He bears a most striking resemblance to Jack; in fact, the older he gets, the more he looks like him. Take a look:
There's a shot of Andy in the final Season 9 episode in which he is wearing a blue suit (all dressed up to attend Jamie and Edit's wedding). Boy! Does he ever look like Jack in his McGarrett suit! The picture changed too quickly for me to get a screen capture of it. Alas!
Blue Bloods gives several tips of the hat to our boy Jack: Sean's brother is named Jack (Jack Reagan is portrayed by Andy's real-life brother, Tony). Then, there's Garrett Moore (Gregory Jbara), the commissioner's assistant for public affairs. And, then, there's Jack Boyle (Peter Hermann), Erin's ex. Too, the Reagans, like the Ryans, are Irish Catholics living in New York. The praise continues for Hawaii Five-0. It is an excellent police procedural. And, besides, one character is named for Governor Jameson -- Jameson "Jamie" Reagan (Will Estes).