Actually, the Aragorn Arwen interspecies relationship is a horrific bummer because after all that Timotei ad stuff and angst and Elrond saying 'Go to your room!' because eternal-life Elf Arwen can't marry a mortal who will die and leave her heartbroken forever -- she does, and he eventually dies, and she's heartbroken forever.
Though (and I realise that it's probably hidden in a footnote in The Silmarillion or something), I don't know whether their children are immortal or not? Because surely that's far grimmer -- to outlive not only your husband but all your children, grandchildren, great-grandchildren.
Don't do it, Arwen. Listen to Daddy and find yourself a nice, safe Elf in the Grey Havens. That way Eowyn, who, let's face it, is waay cooler, kills the King of the Nazgul, and is not acting in a Timotei ad, can have Aragorn instead of well-meaning but slightly drippy Faramir, with whom she only bonds because they're both stuck in hospital at the same time.
Eowyn was a corrupt CIA station chief/double agent in the Berlin season of Homeland, and she was great.