These fools are crazy good:
Morgan (he's so adorable and powerful)
Lucina
Cherche
Lon'qu
Severa
Chrom
The others in my team are good, but not nearly as amazing as these 6 (+MU).
I didn't include more children, because I didn't bother leveling up their parents. Maribelle, Lissa, Sumia, Miriel, and Sully were very much neglected in my game.
edit: second playthrough, I'm thinking about shipping Cherche x Lon'qu, because they're powerful and my favorite supporting characters. In other words, I'm gonna produce an unstoppable Gerome!