Question: Which of the hosts on A-List Listings is not married to Neil Patrick Harris?

Context paragraphs:
Animal Room: Animal Room is a 1995 American drama/thriller film directed, produced, and written by Craig Singer and starring Neil Patrick Harris as a bullied drug-using teenager and Matthew Lillard as the bully who loves to torment Harris's character.  The film is referred to as a modernized version of "A Clockwork Orange" and features an appearance from the punk rock band The Misfits (band).

A Series of Unfortunate Events (TV series): Lemony Snicket's A Series of Unfortunate Events, or simply A Series of Unfortunate Events, is an American black comedy-drama television series from Netflix, and developed by Mark Hudis and Barry Sonnenfeld, based on the children's novel series of the same name by Lemony Snicket.  It stars Neil Patrick Harris, Patrick Warburton, Malina Weissman, Louis Hynes, K. Todd Freeman and Presley Smith.

Brain Games (National Geographic): Brain Games is a popular science television series that explores cognitive science by focusing on illusions, psychological experiments, and counterintuitive thinking.  Neil Patrick Harris was the unseen narrator in the first season, replaced by Jason Silva for the remainder of the series as its host and presenter; in addition, sleight-of-hand artist Apollo Robbins has been a frequent consultant and illusionist guest on the show.  The show is interactive, encouraging television viewers, often along with a handful of live volunteers, to engage in visual, auditory, and other cognitive experiments, or "brain games", that emphasize the main points presented in each episode.  The series debuted on the National Geographic Channel in 2011 as a special.  Its return as an original series in 2013 set a record for the highest premiere rating for any National Geographic Channel original series with 1.5 million viewers.  Season 7 aired in early 2016.  As of 2017, it's unknown whether or not future seasons will be announced.

Too Good to Be True (film): Too Good to Be True is a 1988 American television film starring Loni Anderson, Patrick Duffy, Daniel Baldwin, Glynnis O'Connor, Larry Drake, Neil Patrick Harris, James Sikking, and Julie Harris.  It was adapted for the small screen by Timothy Bradshaw, based on the novel "Leave Her to Heaven" by Ben Ames Williams and was directed by Christian I. Nyby II.  After John M. Stahl's "Leave Her to Heaven", this is the second film adaption of Williams' book.

Prediction Productions: Prediction Productions is Neil Patrick Harris' production company.  It also was one of the production companies involved with Best Time Ever with Neil Patrick Harris.  Harris has a deal with NBC to work on new projects through Prediction Productions as well.

David Burtka: David Michael Burtka (born May 29, 1975) is an American actor and professional chef.  He is known for his acting roles in theatre and television shows such as "How I Met Your Mother" and "The Play About the Baby".  After his role on "How I Met Your Mother", Burtka gained media attention for dating Neil Patrick Harris, whom he later married in 2014.

Neil's Puppet Dreams: Neil's Puppet Dreams is a web series created by The Jim Henson Company under its Henson Alternative Banner and released on The Nerdist Channel.  The series stars Neil Patrick Harris who helped to create the series.

87th Academy Awards: The 87th Academy Awards ceremony, presented by the Academy of Motion Picture Arts and Sciences (AMPAS), honored the best films of 2014 and took place on February 22, 2015, at the Dolby Theatre in Hollywood, Los Angeles beginning at 5:30 p.m. PST / 8:30 p.m. EST.  During the ceremony, AMPAS presented Academy Awards (commonly referred to as Oscars) in 24 categories.  The ceremony was televised in the United States by ABC, produced by Neil Meron and Craig Zadan and directed by Hamish Hamilton.  Actor Neil Patrick Harris hosted the ceremony for the first time.

Best Time Ever with Neil Patrick Harris: Best Time Ever with Neil Patrick Harris (or Best Time Ever) was an American live television variety series adaptation of the British variety series "Ant & Dec's Saturday Night Takeaway".  The one-hour show is hosted and executive-produced by Neil Patrick Harris featuring Nicole Scherzinger as a co-host.  The series aired on NBC from September 15, to November 3, 2015.  On December 15, 2015, it was announced that the show had been cancelled after one season.

A-List Listings: A-List Listings is an American reality television series that debuted October 24, 2012, on E!.  Hosted by David Burtka and Catt Sadler, the series showcases America's most exclusive and extravagant homes.

Supporting paragraphs: A-List Listings David Burtka
Answer: Catt Sadler