The Fire Emblem series has seen quite the resurgence during the last console generation. The once niche series (at least in the West) has exploded in popularity, largely due to the popularity of Fire Emblem Awakening for the Nintendo 3DS. For both long-time fans and especially newcomers, the game provided an excellent FE experience despite some minor hiccups. Even after the release of the excellent Three Houses, Awakening remains an incredibly solid starting point for any player interested in the series.
One of the defining traits of Awakening is the extensive system of marriage and child units. The children of the main cast have subtle stat differences based on their parents, along with inheriting great skills. However, since only female cast members (plus Chrom and male Robin) have children, the parents that make a difference statistically are the male partners. This list ranks the best parents to pair with female party members, along with a couple of outliers for Chrom and Robin.
10 Sumia (For Chrom)
When looking at Chrom's potential partners, all of the options are fairly solid aside from Maribelle. Child units have their base stats and growth rates influenced by their respective parents. In a game where speed is one of the best stats, however, any little edge matters. This leaves both Olivia and Sumia as the best options due to their similar growth rates.
However, since Sumia has significantly better base stats than Olivia, Sumia gets the edge. Making sure Lucina has access to the Pegasus Knight class is particularly useful, since that unlocks her to gain the ability Galeforce. Galeforce allows for two moves in a single turn, which is unmatched in its usefulness.
9 Tharja (For Robin)
For male Robin, there are a number of possibilities for his partner. For example, Cordelia is a solid option, since that gives the potential of passing down the Galeforce ability later in the game. However, in a game that lacks particularly effective mages from an offensive perspective, giving Morgan a magical edge isn't a bad idea.
This means that Tharja, with her high magic and speed stats, works perfectly to offset Robin's average growths. Since Morgan can already obtain Galeforce on her own later in the game, it's not necessary to pair to obtain it. It definitely helps that Tharja's child, Noire, gets stronger as well.
8 Avatar/Robin
Moving onto the male parents to pair, the main character is an obviously good choice. Robin's growths are solidly average, meaning he isn't likely to ruin his child's stat-line. The most important thing a child learns from Robin are his exclusive Tactician skills and the ability to use any class in the game.
This allows for three characters to have the ability to reclass in any way the player would need them to. For casual playthroughs, more variety means more shenanigans can be afoot. On harder difficulties, this can allow the player to shore up weaknesses within the army. Being stuck with Virion as the only archer would be pure misery. Robin is an incredibly versatile and useful parent.
7 Chrom
Chrom's options are limited and his pairing with another unit is literally required for the plot. However, his protagonist powers shouldn't be understated. Chrom's biggest asset aside from solid stats is access to his exclusive abilities. Chrom's daughters will always learn Aether and his son will always learn Rightful King.
Chrom doesn't even need to know these skills himself for them to be obtainable on his children. Both of these abilities are incredibly powerful to have later in the game. Combine them with strong skills for his partner, and it's possible to create an incredibly powerful unit.
6 Lon'qu
As stated before, some of the most useful stats in Awakening are strength, skill, and speed. The Myrmidon Lon'qu excels at two of those stats, along with passing on the skills Vantage and Astra. Both of these abilities are useful on any offensive class. Lon'qu himself is a solid unit overall, being the only unit that starts as a Myrmidon in the first act of the game.
This isn't too bad, since Awakening isn't lacking in sword wielders. His speed growth in particular is unrivaled by any unit except Panne. It's definitely better to pair Lon'qu with a partner whose child benefits from those stats and has the growths needed to shore up Lon'qu's weaker strength stat.
5 Gaius
Gaius is diet Lon'qu statwise; not as fast, but hits a bit harder. In terms of class options, both are nearly identical. However, there are differences that may make Gaius a better option. The first is the skill Locktouch, which is useful but maybe not too effective for combat.
More importantly, Gaius picks up Movement +1 and Lethality if he promotes to be an assassin. Gaining extra movement across the board breaks the relatively small maps of Awakening, and pairs particularly well with any flying or mounted unit. Plus, female children that wouldn't have access to the Pegasus Knight, Gaius gives them that option. The more Galeforce, the better.
4 Frederick
Unlike many pre-promotes in the Fire Emblem series, Frederick is actually a solid unit with solid growths and great base stats. This makes him a solid selection for any child unit that benefits from a defensive statline. On top of that, he gets early access to the Luna ability if he isn't reclassed, which is a boon for any child unit that can make use of it.
The only drawback to using Frederick is that his support conversations aren't very interesting. For players who care about the story and characters and having fun, it might not be the best option. With gameplay, Frederick is a solid, if uninspiring, parent.
3 Henry
Originally, the knight from Awakening was going to be included on this list. However, his name and entire existence is nowhere to be found. It's tragic, really. However, that's fine, because that makes room to include Henry as a parent option. Henry's biggest asset is adding another Dark Mage option on the table for child units. The Dark Mage abilities are incredibly useful to have on units that can fight in melee range.
Although the classes he passes on aside from Dark Mage aren't anything to write home about, Henry still provides solid skill and class coverage. He's a character that should definitely be paired, even though he's picked up later in the game.
2 Gregor
Gregor isn't anything too special aside from a high HP growth; the rest of his growths are below average. However, it can't be understated just how useful the Mercenary abilities are. Armsthrift on units with high luck stats is always a great pickup, since that saves money from having to repair or buy new equipment.
If upgraded into a Hero, Sol is a powerful skill to have. The Bow Knight picks up Rally Skill which, while not amazing, has its uses. Plus, he can pivot to a fighter and actually be useful. Although he isn't the best parent, Gregor also isn't the worst; he's not Vaike, after all.
1 Donnel
This one shouldn't be a surprise to anyone who has played Awakening. Donnel, the villager with a dopey pot on his head, is the slayer of Gods. With already high base stat growths combined with the Aptitude skill, any worthwhile party should bring Donnel along.
As a parent, Donnel passes Aptitude along to his child. There is not a single unit in the game that doesn't benefit from the bonuses gained from Aptitude. On top of this, his daughter can inherit the Pegasus Knight class, which means there's even more potential for Galeforce. Donnel should always be picked up and always be paired, there's no question about it.