That's Adequate is a 1989 mockumentary documenting a fictional Hollywood studio, Adequate Film Studios.
 Narrated and hosted by Tony Randall, the film features an all-star cast including James Coco (in his final film role), Robert Downey, Jr., Anne Meara, Jerry Stiller, Bruce Willis and Ben Stiller.
Benjamin Edward Meara Stiller (born November 30, 1965) is an American actor, comedian and filmmaker.
 He is the son of veteran comedians and actors Jerry Stiller and Anne Meara.
Gerald Isaac Stiller (born June 8, 1927) is an American comedian and actor.
 He spent many years in the comedy team Stiller and Meara with his wife, Anne Meara.
 He later played Frank Costanza on the NBC sitcom "Seinfeld" and Arthur Spooner on the CBS comedy series "The King of Queens".
 Stiller and Meara are the parents of actor Ben Stiller, with whom Stiller co-starred in the films "Zoolander", "Heavyweights", "Hot Pursuit", "The Heartbreak Kid" and "Zoolander 2".
 Stiller is known for his angry, yelling acting style.
Another Harvest Moon is a 2009 American drama film written by Jeremy T. Black and directed by Greg Swartz about four elderly citizens coping with life in a nursing home.
 It stars Ernest Borgnine, Piper Laurie, Anne Meara and Doris Roberts.
 The film was one of Borgnine's last major roles before his death in 2012.
The Independent is a mockumentary comedy film made in 2000, directed by Stephen Kessler and starring Jerry Stiller and Janeane Garofalo.
 Stiller portrays an independent film maker who makes little-known B movies with titles like "Twelve Angry Men and a Baby".
 The film spoofs independent directors and independent film.
 The movie features Max Perlich and cameos by Anne Meara, Ron Howard, Roger Corman, Peter Bogdanovich, John Lydon, Ben Stiller, Andy Dick, Fred Dryer, Jonathan Katz, Fred Williamson, Karen Black, Nick Cassavetes, Julie Strain and adult film actress Ginger Lynn.
 The fictional career of Morty Fineman (Stiller) includes having made 427 films, although it is not specified as to whether he directed them all or if it refers to films produced or written by the Fineman character.
 The theme song "The Love Song For 'The Independent"' is performed by Nancy Sinatra.
Southie is a 1999 American film directed by John Shea and starring Donnie Wahlberg.
 The film centers on Danny Quinn (Wahlberg) who returns home to South Boston from New York City and gets stuck between his friends, who are supported by one Irish gang, and his family, which are members of another.
 The film also stars Rose McGowan, Anne Meara, Will Arnett, Jimmy Cummings, Lawrence Tierney, Robert Wahlberg, and Amanda Peet.
Doreen Cannon (21 October 1930) was born and raised in New York City.
 She trained as an actress at the HB Studio in Manhattan for over 10 years with the famous Uta Hagen and Herbert Berghof.
 Her contemporaries and fellow students were Peter Falk, Geraldine Page, Sandy Dennis, Maureen Stapleton, Anne Meara and Jerry Stiller.
 She appeared in many plays off Broadway and in Summer Stock alongside such stars as Dorothy Lamour, Robert Alda, Alan Alda and Basil Rathbone.
 She married an English Property Developer David Cannon in NYC and came over to London in 1959.
 She was subsequently invited by George Devine to teach master workshops at The Royal Court Theatre.
The Stiller and Meara Show was a proposed 1986 television sitcom featuring the comedy duo Stiller and Meara (Jerry Stiller and Anne Meara) as the deputy mayor of New York (Stiller) and his wife, a TV commercial actress (Meara).
Anne Meara (September 20, 1929 – May 23, 2015) was an American actress and comedian.
 Along with her husband, Jerry Stiller, she was one-half of a prominent 1960s comedy team, Stiller and Meara.
 She was also featured on stage, television, in numerous films, and later became a playwright.
Stag is a 1997 American thriller film, directed by Gavin Wilding, made for HBO and later released theatrically after drawing large ratings.
 "Stag" features an ensemble cast including Ben Gazzara, Andrew McCarthy, Taylor Dayne, Mario Van Peebles, Lawrence Leritz, William McNamara, John Henson, Kevin Dillon, and Jerry Stiller.
 It was produced by Lions Gate Entertainment.

Question: Stag features an American comedian and actor who is married to Anne Meara, and who played Frank Costanza on what sitcom?
Answer: Seinfeld