Fire Emblem: Three Houses is an excellent tactical RPG, with plenty of interesting classes and characters to build a complex story and dynamic fights. While this is indisputably the core of the game, fans often point to another incredibly important aspect of Three Houses that absolutely shouldn't be overlooked. This is, of course, the dating sim.
Not only do players get to pair up all of their units, but Three Houses gives the main character, Byleth, plenty of potential romance options. Choosing which character to 'S-Rank' is arguably just as vital as any of the other strategic decision in the game, especially given how many of the best characters--like Edelgard, Mercedes, and Linhardt-- are possible suitors for both male and female Byleth. With Fire Emblem: Three Hopes on the horizon, players may be picking up Three Houses again and revisiting the question of which character is best for Byleth.
Claude
Of the original Lords, Claude has probably the most objectively healthy relationship with Byleth--one of the many reasons Claude is an indisputable Three House's fan favorite. Edelgard and Dimitri can arguably skew a little co-dependent, and definitely come with a pretty hefty amount of baggage, but Claude makes it clear that he values Byleth without making her his entire life.
Besides his undeniable charm, Claude's unique perspective, optimism, and absolute dedication to his cause make him a compelling character more than worth getting to know. While some players note that their S Support can come off as platonic, most agree that their ending stays true to Claude's character and goals while still expressing how important his relationship with Byleth is to him.
Hapi
One of the DLC characters, Hapi and Byleth share the dubious honor of both being the product of the Church's human experimentation. While Hapi's curse is undoubtedly the more dangerous, she manages to still maintain an upbeat personality with plenty of good humor. Their shared circumstance leads to Hapi feeling comfortable and safe around Byleth in a way she doesn't with anyone else.
The highlight of Hapi's S Support comes with Byleth's proposal. Not simply offering a ring, Byleth gives Hapi a way to be free from her curse and finally live without constantly feeling like a danger to others. It's an excellent ending for Hapi, who has always felt shackled by her ability, and their end card's description of their peaceful lives sounds like an idyllic future for both characters.
Mercedes
Despite being taken advantage of because her crest, Mercedes never loses her unrelenting care for others and her desire to help wherever possible. This leads her to always put others before herself, and Byleth makes her more confident to follow her own desires and happiness. However, just because Byleth is the one to inspire her decision, Mercedes makes it clear that that doesn't mean she is now choosing to live for Byleth instead.
Part of the charm of their romance is seeing that, despite how sweet and kind she still is, Mercedes has grown to stand firm in her own convictions and self-worth and tells Byleth in no uncertain terms that she may be 'quite demanding at times'.
Dorothea
Dorothea is one of Three House's most popular recruits and an indisputable fan favorite, shining both for her prowess in the indispensable 'dancer' class and her incredibly endearing personality. An orphan who lived in extreme poverty and reached success at the cost of being consistently objectified, Dorothea's experiences cause her to feel trapped into playing up a facade so she can secure a 'beneficial' marriage.
One of the highlights of Dorothea's romance is how well it resolves her personal arc. Throughout her supports, Dorothea makes it clear that she feels like Byleth sees her true self, and demands honesty from Byleth in return--putting their relationship on a more equal footing. This culminating in a romance has Dorothea firmly escaping the fate she feared and getting to realize her dream of marrying for love.
Dimitri
Dimitri is so clearly infatuated with Byleth at the start of the game that many fans find their romance to be a natural conclusion. From what starts off as a starry-eyed crush, Dimitri comes to rely on Byleth as a pillar of emotional support and guidance. Byleth is the person Dimitri confides in about his need for revenge and violence following the trauma of his youth, and, more importantly, the shame he feels about those impulses. Their understanding and compassion in this moment is most likely what ultimately saves Dimitri later on.
Dimitri's storyline is one of the most tragic in Three Houses, and many fans have talked about the emotional impact of his fall from idealistic chivalry to traumatized bloodlust. Dimitri is able to find himself and begin healing because of Byleth's determination to reach out to him and he returns this devotion by remaining by her side no matter what.
Jeritza
Added as a free DLC character, those who played the game before Jeritza's release most likely had plenty of preconceived notions about the man behind the Death Knight. Initially underrated, the reality of Jeritza's character exceeded expectations, with his delightfully unexpected sweet tooth, appropriately angsty backstory, and incredible combat prowess. His availability as a romance for both Byleths was more than welcomed.
Possessed by a creature of death, Jeritza understands his relationship to others through violence, and Byleth is no exception. In fact, it's Byleth's own capacity for killing that initially captures Jeritza's attention, having finally found someone who could potentially be a challenge to him. Jeritza's Support line is one of the most explicitly romantic in the game, and its macabre tone sets it apart from any of the others--at the price of being potentially off-putting to some players. Nevertheless, its popularity has proven that plenty of fans find a death pact to be just as romantic as a proposal.
Linhardt
At the game's release, Linhardt was the only male romance option for male Byleth. While many fans were critical of this disparity, most found Linhardt's supports themselves to be far from disappointing. Initially coming off as simply lazy, Linhardt shows himself to be one the most introspective and complex of the characters, engaging Byleth in ethical questions about the violence which most others seem to take for granted.
Linhardt's Romance is both thought-provoking and entirely wholesome. While still questioning the necessity of violence and its larger implications, Linhardt's promise to work alongside Byleth so that they can one day find peace is undeniably sweet.
Marianne
Marianne is known for being much more than she initially seems, and plenty of players have found themselves surprised by how much depth her character really has--with her paralogue consistently praised as being amongst the best in Three Houses. Initially reclusive, anxious, and easy to overlook, Marianne starts the game in a profoundly dark place, secretly struggling with the hardships of her Crest and a deep sense of hopelessness. However, Byleth's belief and support helps Marianne see her own worth and begin to move past the fears her Crest had embedded in her.
Marianne's arc and her happiness during her S Support is incredibly endearing, but a particular highlight of her romance is the proposal scene. Not only is it incredibly sweet, but Marianne gathering the courage to propose to Byleth first is an excellent portrayal of just how far she's come.
Yuri
From just his role in the DLC mission alone, Yuri proved himself to be a complicated, mysterious character. Coming across as both the crime boss of the Abyss and its Robin Hood, Yuri starts off with his loyalty and concerns entirely vested in the well-being of the Abyss and is mostly distrustful of Byleth. He's openly flirtatious, but this is clearly a mask he puts on to protect himself and his secrets.
Getting to know Yuri has the dual benefit of peeling away his guarded layers and false airs to reveal his more vulnerable side while also learning more about life in the Abyss. Despite his exterior, Yuri clearly has a deep love and attachment for the people he cares about, and Byleth slowly becoming one of them makes his S Support especially endearing.
Edelgard
Edelgard is likely the most divisive character in Three Houses, and the hardest to successfully romance--although she is the only Lord that can be S-ranked by both Byleths. However, none of this difficulty is due to Edelgard playing hard-to-get and, in fact, she is quite clearly besotted with Byleth from the jump and cares deeply for them no matter what route.
What makes Edelgard's relationship with Byleth so significant is that it gives the player a chance to get to know one of the game's most complicated characters and understand, and even support, her motivations and reasoning. Edelgard's supports reveal a side to her that the player can't get anywhere else in the story, unpeeling the girl who is treated as a tyrant in the other routes to reveal her kindness, vulnerability, and the crushing weight of the responsibilities that she has taken up. Edelgard gives Byleth the chance to be free from fate and live on their own terms.