BatCat forever!
Bale, Hathaway, and the Nolans got it.
2nd place goes to Harvey/Rachel followed by Bruce/Rachel mainly because Rachel had a major on switch as soon as Harvey was in trouble. And besides being Bruce's one hope for a normal life, what was she to him? Based on how she was going by the book they seemed to be losing most of their connections to each other.
Bruce/Miranda was just Bruce lonely at the mention of lost loved ones (specifically Alfred being gone so he had no one), [BLACKOUT]Talia trying to screw with Bruce's head (hey let's escape so I can secretly plot to destroy Gotham and bring you back so you can feel the heat as... blablabla)[/BLACKOUT], and Bruce worried about the person who was supposed to help him with the Wayne legacy being [BLACKOUT]stuck in No Man's Land Gotham[/BLACKOUT]. I'd hardly call it a real relationship.
Bruce/Gordon would be a total win if I was a fan of slash not originally in the story.
I'm surprised no one picked Bats and the Joker.