Tim Drake and Conner Kent. DC even did an article on the fans for them as a couple some months back.
Damien Wayne and Jon Kent - when they're both of the right age. I thought someday they could be a couple when they were older, but then they aged Jon up and sent him to the future. Let Damien catch up in age when the time is right. At this point they are both are pretty blank slates so there's not a lot of romantic history in their way. Saturn Girl is trying to mess with this, I know.
DC really needs an A list gay man, on the same level as Batwoman. As it is, their gay men are supporting characters and except for Aqualad I believe they're all in limbo somewhere.