answering more thinking of eros rather than purely what i think is most romantic and deeply written...

the pirate girls from tail concerto all dating each other

chocolat and elh from solatorobo

tails and klonoa was one i really liked as a teen especially because of a doujin...

tailmon and kari....

blaze the cat... there's two characters i like to ship her with. i'll let you figure out who....

actually that reminds me for the longest time i hated silver the hedgehog for being a male ship to blaze but honestly i am okay with the ship now. lovers whose love was erased by reality and they're now strangers from completely different worlds now but somehow they're still destined to be together despite everything is one hell of a powerfully romantic trope. i also just like silver a lot as a character now