You've got:
The Brave and The Bold (a GL and a Flash)
Royalty (Aquaman and WW)
The Birds of Prey (Huntress and Canary)
Lots of Variations on the World's Finest Families (IE Superboy and Robin, Batgirl and Supergirl, Huntress and Power Girl)
As for stuff I'd love to see:
John Stewart and Jesse Quick. Both are somewhat outcasts amount their families. I think they'd make a good mix and a great take on the Brave and the Bold.
Capt Marvel (Billy) and Nightwing. Both grew up in the costume, from child to adult. I think theres alot of uncharted ground there.
Kyle Rayner and Jason Rusch. Again, alot of similarities, in the sense that they had this legacy thrust on them without asking for it.