Superman and Batman are best friends. In Justice League issue 9 written by Geoff Johns, they're such close friends that Batman just calls Superman to hang out on a mission. And their friendship has even produced a long-running Superman/Batman series.
Green Lantern and Flash are best friends too. They get along better than anyone else on the Justice League, and they seem to team up together very often.
So I think it wold be cool if Wonder Woman and Cyborg became best friends. They could hang out, share experiences, and team up. Maybe they could even be co-workers if they both work for A.R.G.U.S. Cyborg could work for the Red Room while Wonder Woman works for the Black Room or the Circus.
Plus, they have a pretty cool dichotomy. Superman and Batman are Light and Darkness. Green Lantern and Flash are Space and Time. Wonder Woman and Cyborg would be Antiquity and Modernity. And all 3 pairs have an Outer Space Hero/Earth Hero dichotomy. Now that's symmetry!
What do you think?