The only reason why I don't ship Galadriel w/ Halbrand is because, once she rejected him, he threw her into the water to die.
That scene revealed his true nature, and one which has been repeatedly demonstrated in the books: Sauron is treacherous. He will betray and discard even faithful allies if it suits his agenda.
Which is why I'm fully convinced he never intended to have Galadriel become his wife. Sure, he admired her determination, but he also detested her stubborness and lack of emotional intelligence - as shown by his numerous criticisms of how she handled most situations.
He knew from the start she was hunting him. So at some point, he realised that elf woman would be trouble. Because he lacked the means to dispose of her, he didn't take action against her. If anything, he needed power, and maybe hanging with her would help him somehow. And it did. It got him to Númenor, and later, got him access to Celebrimbor and the forging of three of the great rings.
However, he knew sooner or later, he would have to figure out a way to neutralize the threat Galadriel posed. So he appealed to his charm, something which had worked quite well on the other elves. He hoped his offer of power would appeal to her, not because he admired her for her qualities, but because it was a strategic decision.
And Galadriel, knowing the enemy as well as she did, made the smart choice.
Now, a lot of people watched that scene and thought it was romantic. But no romantic thoughts were going on in Sauron's mind at that moment. The only thing he was thinking of was of his survival and the success of his long term plan to reconquer Middle Earth. If Galadriel were an innocent, love-starved individual, she would have fallen for Sauron's trickery. Thank Ilúvatar she was an experienced General capable of staring at the face of Evil and recognising it for what it is.