She's a NYPD homicide detective and he's a best-selling mystery author. Though the partnership is a bit of a leap, their chemistry is excellent.

Jonathan Hart (Robert Wagner) and Jennifer Hart (Stefanie Powers) in Hart to Hart (1979-1984).

The Harts were a wealthy, jetsetting couple who found themselves constantly playing sleuth to a succession of crimes.

Elliot Stabler (Christopher Meloni) and Olivia Benson (Mariska Hargitay) in Law & Order: SVU (1999-present; Meloni left in 2011).

Though the series has featured many partnerships, none were as brilliant as Stabler and Benson.

Tommy Beresford (James Warwick) and Tuppence Beresford (Francesca Annis) in Agatha Christie's Partners in Crime (1983).

Based on a series of Agatha Christie novels; remade in 2015 with David Walliams and Jessica Raine.

Maddie Hayes (Cybill Shepherd) and David Addison (Bruce Willis) in Moonlighting (1985-1989).

One of the sharpest, most original comedies of all time, loaded with sexual tension, about an unlikely pairing of private eyes.

Frank Hardy (Parker Stevenson), Joe Hardy (Shaun Cassidy) and Nancy Drew (Pamela Sue Martin, later Janet Louise Johnson) in The Hardy Boys/Nancy Drew Mysteries (1977-1979).

Based on the books by Franklin W. Dixon and Carolyn Keene.

Marty Hart (Woody Harrelson) and Rust Cohle (Matthew McConaughey) in True Detective (2014-present; they appeared only in 2014.)

Brilliant writing, brilliant casting and a stunning partnership between two Louisiana cops.

Sherlock Holmes (Benedict Cumberbatch) and Dr John Watson (Martin Freeman) in Sherlock (2010-present).

Critically exalted, contemporary reboot of Sir Arthur Conan Doyle's series of mystery novels.

Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) in The X-Files (1993-2002).

A sceptic and a believer tackle UFO cases. One of the most successful series of the 1990s, returning in 2016 as a limited series.

Sherlock Holmes (Jonny Lee Miller) and Joan Watson (Lucy Liu) in Elementary (2012-present).

A gender-bending twist on Sir Arthur Conan Doyle's novels about a detective and his sidekick, transplanted into modern-day New York.