I have my own theories, but I'd love to hear from what the community in general thinks! (And apologies in advance if this question has already been done to death years ago!)
Edit: I'm still getting used to Livejournal, so I put all my thoughts on Hornblower characters and Hogwarts houses in a comment. It looks like they'd fit better here in the main post, so I've just added them to the main post.
As I'm in a hotel room after giving a talk and wanting to decompress before sleep, I'm going to go ahead and post my (very preliminary) thoughts on Horatio Hornblower (TV) characters and Hogwarts houses:
I think Horatio would be either Slytherin or Gryffindor, and that Archie would be either Hufflepuff or Gryffindor. I'm not sure about Bush, but I'm contemplating him as a Hufflepuff.
Here's the justification:
Horatio & Slytherin (characteristics: cunning, resourcefulness, and ambition): Horatio is REALLY ambitious and competitive. When Styles gives Horatio his first salute, Horatio's response is not surprise or imposter syndrome, but rather, a desire for more recognition and to keep gaining accolades: "Well, that's a start, I suppose." Horatio also plays fast and loose with the rules of war (e.g. all those times he flies the wrong flag or pretends to not be English to trick the enemy), and when called on it, explicitly says "I play to win." He also thrives on plans/cunning (even though many of them don't quite work). I think he becomes even more Slytherin like in the final two movies when he continues down the path begun at the end of "Retribution," where he's willing to participate in political cover-ups for the sake of the "greater good."
Horatio & Gryffindor (Characteristics: bravery, determination, chivalry, recklessness):
Horatio is consistently brave and rather reckless when it comes to his own personal safety: he challenges Simpson to a duel, jumps on the fire ship, jumps off the cliff, smothers the fuse of a cannonball, etc. He also acts chivalrous towards Mariette and Maria (when he’s not be horrible to Maria after they’re married, that is). He also has the savior complex that is common to Gryffindors (see: Davy Williams, Finch, Bunting, Archie).
However, he also plans a LOT more than most Gryffindors (e.g. the ploy with the map and compass in “Even Chance”) and is generally more hesitant than most Gryffindors to act (look at how long it takes him to decide that Sawyer shouldn’t be in command).
Archie and Hufflepuff (Characteristics: Dedication, Loyalty, Fair Play, Honesty, Kindness, Tenaciousness)
I want to say from the outset that this is not meant as derogatory to Archie, who will always be one of my favorite fictional characters: Hufflepuffs got the short end of the narrative stick in Harry Potter, but that’s not anything wrong with people from that house.
Archie is incredibly dedicated and loyal to Horatio: he tries to commit suicide to save Horatio when he thinks he’s endangering him, and then lives because Horatio tells him he needs him. He repeatedly risks his life for him (the bridge and blowing up the fort), and then finally sacrifices his life and name to keep Horatio from endangering himself. Because of his own history as an abuse victim, Archie HATES it when people abuse their authority or treat people unfairly (as everything with Wellard shows). He’s also incredibly kind (see: Horatio and Wellard) and determined (he survives under impossible circumstances and drags himself to a courtroom to confess to something he didn’t do when he can barely stand).
However, Archie isn’t patient or impartial.
Archie & Gryffindor (Characteristics: bravery, determination, chivalry, recklessness):
It takes incredible bravery and determination to choose to live after everything Archie has been through. Archie also has a history of recklessness (the bridge, blowing up the fort, mouthing off and being the first to bring up mutiny to Horatio, the court room), which would seem to align him with Gryffindor.
However, all his reckless actions are to keep Horatio safe, and are therefore borne out of loyalty, which might suggest that he’s more of a Hufflepuff.
William Bush & Hufflepuff (Characteristics: Dedication, Loyalty, Fair Play, Honesty, Kindness, Patience, Tenaciousness):
Bush appears to be incredibly loyal to Horatio, is patient with Buckland and Sawyer, and appears invested in following the rules/fair play, almost to a fault (in “Mutiny”).
So, I think that a lot of the different house options could work, especially since Archie and Horatio change so much over the course of the show. What do you all think?