Emily Thorne (Revenge) and Jake Ballard (Scandal)
They're both badass spy types capable of subverting the law to get what they want. Emily Thorne would work amazingly well in the world of Scandal.
Captain Sean Renard (Grimm) and Agent Melinda May (Agents of SHIELD)
Sean Renard is a powerful man who faced terrible odds just to survive to adulthood as a half-Wesen bastard of a Royal Family. He doesn't trust easily, thanks to his family constantly trying to undermine and/or kill him, but he maintains a steely integrity while keeping order in Portland. Melinda May is just the sort of strong woman he needs in his personal life: perceptive, physically capable, and able keeping a secret while still standing up to him if he goes too far. Plus, imagining their sparring sessions is epic.
Rosa Diaz (Brooklyn Nine-Nine) and Nick Miller (New Girl)
Neither like to show emotion. Both have close relationships with a Jewish person.
Cami (The Originals) and Dean Winchester(Supernatural)
Both have complicated pasts and undeniably useful in a sticky situation, Cami with her incredible insight and brains and Dean with his vulnerability and ass kicking.
Bash (Reign) and Sansa Stark (Game of Thrones)
Bash may be a bastard but he's the sweetest, most passionate bastard that ever lived and a perfect foil for the spoiled, beautiful and increasingly clever and resourceful Sansa.
Cristela (Cristela) and Doug (House of Lies)
Cristela is strong, funny and smart while Doug is equally smart and funny but easily manipulated. Cristela would be the supportive and loving partner Doug truly needs but doesn't know he wants without taking his balls away.
Maura Isles (Rizzoli & Isles) and Spencer Reid (Criminal Minds)
They would be an interesting pair. Both are super smart, socially awkward, and fiercely loyal. Plus they're both doctors.
Rick Grimes (Walking Dead) and Norma Bates (Bates Motel)
They are both survivors with highly questionable parenting styles. They're both single parents, with one raising a psychopath and the other a borderline sociopath. But Norma could baby Carl, because he really just needs a mother, right? And Rick could get Norman killing people who are already dead. It's just a win-win for everyone.
Matthew Crawley (Downton Abbey) and Elena Gilbert (The Vampire Diaries)
They are/were incredibly loving people. Of course now that one is dead and one is a vampire. If only the other side hadn't been forever altered on TVD, they might have been able to meet. Hey -- stranger things have happened!
Jeremy Gilbert (The Vampire Diaries) and Octavia Blake (The 100)
Both are badass, fight for what/who they believe in, have similar senses of humor, are a little broken by circumstance, in the shadow of an older sibling, and at the same time, they are both softies when it comes to the people they love.. And they would look great together if that counts for anything!
Cole Lockhart (The Affair) and Laurel Lance (Arrow)
Both of them have had their hearts stomped on and have major flaws, but they're fiercely loyal with good souls. Cole needs someone to keep him from falling into the criminal underworld and Laurel needs someone to support her endeavors. Plus, they'd be really hot together.