From a post from Gamefaqs:
Owain: Ricken, Henry, Libra, Virion
-Owain is actually pretty solid even with his base classes, basically just being Inigo without Mercenary skills and worse caps. Ricken is probably his best choice for overall variety, giving him a whopping +5 magic cap, Cavalier for Luna, and Archer for the option of doing Longbow Lethalities. Henry and Libra offer Dark Mage, which has good synergy with Owain's skills, letting him run the famous Vantage/Vengeance/Wrath combo. If all else fails, Virion is actually an okay choice too, adding several breakers, the Archer tree, and Lifetaker to Owain's arsenal.
Inigo: Chrom, Libra, Virion, Vaike
-Inigo already starts with everything he needs, so this is really more for caps than anything else. Chrom does give him Rightful King, though, which is notable. Virion is also a pretty good choice if you want, giving Inigo most of the Faires, most of the Breakers, Lifetaker and other fun things. Libra gives Inigo a good niche as a mage, thanks to getting Vantage/Armsthrift/Wrath naturally. Vaike is just for caps because unlike most of the other kids, Inigo already starts with the class set he needs, so he couldn't give a rat's ass who his father is.
Brady: Henry, Libra, Lonqu, Kellam
-Brady's class set is pretty good on its own. His main issue, though, is that none of his possible fathers' classes really synergize well with them. Henry is generally considered the best choice due to Axefaire and having the option to go Sorcerer. Libra is basically Henry-lite with similar caps and with Sorcerer still on the table. Lonqu gives good utility classes and okay caps, and Kellam can make him a tanky support character with Aegis/Pavise.
Kjelle: Donny, Gaius, Kellam, Vaike
-Kjelle loves Donny's class set more than anything, so Donny is the obvious choice, giving her Galeforce, Renewal and Dual Support+ in case she needs to shift into a support role on the team. Gaius is good if she wants to go Assassin, too. Kellam, by contrast, is better for a more tanky set due to being able to pass down Renewal. Vaike is here in case you want Donny for someone else, since he still gives her access to Armsthrift and has arguably better caps, along with passing down Axefaire should you want to use all Helswath all the time.
Gerome: Gregor, Kellam, Frederick, Vaike, Gaius, Stahl, Henry
-Gregor offers the best Gerome overall, giving him access to the Mercenary and Myrmidon class trees for Armsthrift/Vantage/Sol shenanigans. Kellam is better for a defensive supporting Gerome with Dual Guard, Renewal, and Dual Support as well as access to Thief. Frederick is much of the same, except he gives the trade-off of Thief for Aegis, which isn't a bad trade considering Cherche's horrid Res and Wyvern Lord's flying weakness. Vaike is a more balanced choice, combining Kellam's Thief support with Gregor's approximate caps and Berserker. Gaius is okay too thanks to giving Vantage and good speed. Also, if you haven't paired him yet, Stahl is arguably one of the better fathers for Gerome. He gives Cavalier and Myrmidon for Vantage/Sol and Aegis, Luna and Dual Guard+, Archer for Bowbreaker, and his caps are fantastic. Lastly, Henry is basically Vaike in case you've gone completely insane and decided not to pair him up with someone who wants the Sorcerer skillset for their kid like Lissa or Maribelle or Sumia.
Yarne: Gregor, Stahl, Vaike, Donny, Gaius
-Gregor again gives Yarne the best skillset. Unfortunately, any father other than Gregor makes Yarne pretty bad either class-wise or cap-wise, since only the Avatar can give Yarne a good setup from that. Stahl is probably the second choice, since Yarne makes good use of all of Stahl's class options and gets pretty good caps out of the deal. Vaike has good caps, too, if massive class redundancy. Donny, though usually reserved for Kjelle or Noire, is actually not a bad choice for Panne, since he gives Mercenary and Aptitude and actually has pretty good caps. Gaius also gives Vantage + Sol for healing.
Laurent: Lon'qu, Stahl, Kellam, Ricken, Gregor
-Laurent's niche is basically a fairly strong glass cannon mage without Galeforce. Lon'qu gives him fantastic caps (+4 magic and +5 skill and speed) and gives the Myrmidon tree for Vantage and the Thief and Wyvern trees for extra utility. Lon'qu's bad defensive caps actually work in Laurent's favour, since it's easier for him to set up the Vantage/Wrath/Vengeance combo as a result. Stahl is a decent choice if only for Myrmidon. Kellam is good if you want a bulky staffbot, and his skillset works well in getting rid of Laurent's traditional squishiness. I also put Ricken on here for massive magic growth, but his class set is kind of wasted on Laurent since he's not really designed to be tanky and he needs Vantage if he wants to go Sorcerer. Gregor is here for Vantage/Armsthrift/Wrath/Vengeance shenanigans, so he's not a bad choice either. I personally prefer Lon'qu, but Gregor lets Laurent do more.
Noire: Ricken, Lon'qu, Gregor, Donny, Gaius, Vaike
-Ricken is probably the best father for a magic Noire because of his growth and being able to bring some actually interesting class options to Noire, such as Aegis and Tomefaire. Lon'qu is also okay due to Vantage and Tharja's natural bulk offsetting his penalties slightly. Gregor is okay, too, but he's also able to pass down Wrath for a build similar to Laurent or can let Noire go physical as well. Donny is a bit of a last resort choice since while he gives Galeforce and Armsthrift, all Noire will really be able to do is Nosferatank since she lacks Vantage or Wrath. Donny does give her the option to go Dark Flier, though. Gaius gives her Galeforce, Sol and Vantage but murders her magic caps, so only use Gaius if you're going physical. Vaike is okay too if you're using a physical Noire, since he gives her good mixed caps and a good class set.
