Floyd Pinkerton: /points to source material. nuff said.

Halloween Jack: He's a good guy, wants to provide for his tribe and save his species, but he doesn't do romantic love. and his species doesn't really do monogamy, anyways.

Roboute Guilliman: Money, power, privilege. He'll give you your own planet without a second thought. and he'll love you with all of his hearts. ... but he's also a deeply lonely, traumatized demigod warlord, and if you marry him, you are his. for the rest of your life. (if not longer.) if you think that's romantic? sure.

Radut Yet-Unblooded: ..........he is a baby chaos astartes bought up by a rogue trader. the crew is still working on him not biting chunks off of people. even "civilized," he's got the maturity and personality of a feral teenage boy.