My favourite non-canonical pairings would have to be:
Aideen x Beowulf
Good growths for Lester. And Rana will be Rana. Same skillset as Midayle but no inheritance of bows. Nothing a Strength Ring can't fix. You'll get better weapons soon enough.
Ayra x Jamuka
I really enjoy this one. Jamuka has good growth rates to pass on, minus skill. But that one is fixed by the minor Odo. Good skillset (all multi-hitting skills for both kids), but Skasaher won't inherit swords. His default weapon is fine for the first two chapters or so, though.
Lachesis x Azel
Really enjoy this one. Pursuit is there, so the kids won't get screwed up. And thanks to the minor Hezul, strength is not a problem either. Azel can pass on up to rank B swords, so plenty of options there. Nanna becomes a better healbot thanks to minor Fala. I really like it.
Sylvia x Lex
I usually pick Sylvia's husband last, really. Lex will do just fine. Elite will come in handy for both Lynn and Corple. And the Defence boost is nice.
Fury x Claude
Sety becomes a major powerhouse, even without Holsety. He absolutely kicks ass with his Light tome. He also becomes the best healer in the game. Though Rana may win that title due to availability. But you can't go wrong with this pairing.
Tiltyu x Levin
Arthur with Holsety and Tinny with Tron/Tornado. Enough said. Pursuit Ring can go to either kid, both are happy to have it.
Bridget x Holyn
This one REALLY helps Patty. She can inherit up to rank B swords, which is much better than her standard C. The Hero Sword will help her tons. Faval will be awesome no matter what. The Ichieval does that. Too bad Faval can't use Moonlight Hit.
