User blog comment:Leena1445/Pairs/@comment-5574752-20121114222744/@comment-1038387-20121114225719

So far, we've seen GA and Canary, Bats and Talia (though that's over), Roy and Jade, Orin and Mera, Mal and Karen, Flash and Iris and the Hawks. Not counting Jay/Joan and Kent/Inza.

Comics couples (both big and obscure) where we've had both parties, but no official couple (yet):
 * Batman and Zatanna
 * Superman and Lois Lane
 * Hal Jordan and Carol Ferris
 * Artemis and Icicle Jr.
 * Captain Atom and Catherine Cobert
 * Babs and Nightwing/Robin
 * Babs and Jason Bard
 * Robin/Tim and Steph
 * Superboy and Wonder Girl
 * Canary and Pieter Cross
 * Impulse and Cissie
 * Lori Lemaris and Ronal
 * Superman and Maxima

And probably some more.