Hugh Laurie wears a Casio Pathfinder

For a long stretch in the middle of the series, the watch on Gregory House's wrist isn't the Hamilton most fans remember. It's a Casio Sea Pathfinder, reference SPF40-1V: a black resin case and matching resin strap, the sort of chunky field-and-dive-styled digital Casio has made for decades. Casio's marketing agency at the time, Propaganda GEM, placed it deliberately, putting the watch on television's most-watched character right as season four premiered in a post-Super Bowl slot that drew 29 million viewers; the season that followed averaged more than 17 million a week.

Inside the story, the watch belongs to Lawrence Kutner, the new fellow House recruits that same season, who gives it to him as a gift. When Kutner takes his own life the following season, Wilson notices House still wearing it and says so out loud: "you're wearing his gift." House keeps it on through the emotional wreckage of that arc, only setting it aside once he starts seeing Cuddy, before the original Hamilton Khaki Field King returns to his wrist in the show's later years.

It's a rare case of a placement deal and a piece of writing lining up: a watch a real marketing team paid to put on House becomes, in the show's own internal logic, a dead colleague's last gift.