Michelle and Barack Obama. Setting all politics aside, they have an admirable relationship and have raised to lovely daughters. They like and respect each other, and were wonderful, decent role models for the youth of the USA. Eight years in the White House and no scandal, even though there were people who tried hard to find some dirt on them. I think they are an amazing, influential, respectable, family-focused couple. (If you want to argue, take it to the Controversial Topics board.)
"Couples" (duos?) that made iconic music in the 60s/70s: Simon&Garfunkel, Ike&Tina Turner, The Carpenters, Everly Brothers, Sonny&Cher, Captain&Tenille, Flatt and Scruggs, etc. Personal relationships might not have been great, but they made some darned fine music!
Dance Couples- Baryishnikov & Kirkland, Fred Astaire & Ginger Rogers, Patrick Swayze and Jennifer Grey... you get the idea, and the theme extends to Ice Dancing, DWTS contestants, etc. We are a dance family so ALWAYS appreciate great dancing!