Owen Brenman (born 17 December 1956 in London) is an English actor best known for his role as next-door neighbour Nick Swainey in the multi-award-winning BBC sitcom "One Foot in the Grave", which ran for ten years (1990–2000) and was written by David Renwick.
 He currently plays Dr. Heston Carter in the BBC drama series "Doctors"
Lou Cutell (born October 6, 1930) is an American movie and television actor.
 He portrayed the proctologist, Dr. Cooperman, in "The Fusilli Jerry" episode of the television series "Seinfeld" and Leo Funkhouser on "Curb Your Enthusiasm".
 Among cult movie fans, he is best known for his portrayal of Dr. Nadir in "Frankenstein Meets the Space Monster", and he can be briefly seen in "Pee-wee's Big Adventure" as Amazing Larry.
 In 1998, he also played a small role in "The Odd Couple II" as Abe, one of Oscar Madison (Walter Matthau)'s card-playing friends in Sarasota, Florida.
 Recently, he was a series regular on the NBC show, "Betty White's Off Their Rockers".
 In 2013, he appeared on the "How I Met Your Mother" episode "Last Time in New York".
Day One is a made-for-TV documentary-drama movie about The Manhattan Project, the research and development of the atomic bomb during World War II.
 It is based on the book by Peter Wyden.
 The movie was written by David W. Rintels and directed by Joseph Sargent.
 It starred Brian Dennehy as General Leslie Groves, David Strathairn as Dr. J. Robert Oppenheimer and Michael Tucker as Dr. Leo Szilard.
 It premiered in the United States on March 5, 1989 on the CBS network.
 It won the 1989 Emmy award for Outstanding Drama/Comedy Special.
 The movie received critical acclaim for its historical accuracy despite being a drama.
Thomas Christopher "Chris" Parnell (born February 5, 1967) is an American actor, voice artist, comedian, and singer.
 He is best known as a cast member on NBC's "Saturday Night Live" from 1998 to 2006 and for his role as Dr. Leo Spaceman on NBC's comedy series "30 Rock".
 In animation, he voices Cyril Figgis on the FX comedy series "Archer" and Jerry Smith on the Adult Swim sci-fi comedy series "Rick and Morty".
 He is also notable for his voice work on the animated PBS series, "Wordgirl", particularly as the narrator.
 He also voices "The Progressive Box," in a multitude of spots featuring the character, in Progressive Corporation insurance advertisements.
Michael Tucker (born February 6, 1945) is an American actor, voice actor, author, and producer perhaps best known for his role on the NBC television series, "L.A. Law".
Caleb Chan is a Canadian composer and multi-instrumentalist.
 He is best known for his work on the animated series "", its "" spin-off, and "Littlest Pet Shop".
 He has also composed for the Sprout network series "Nina's World" as well as the Disney series "Dr. Dimensionpants".
 For his work on Nina's World, he was nominated for a 2016 Leo Award for Best Music in an Animation Program along with composer Daniel Ingram.
 At the start of "" in 2014, Ingram, who is the songwriter for the show, announced that Chan will be the song orchestrator on the series from that point onward.
 For their work on My Little Pony, they were nominated in 2017 for a Leo Award for best musical score.
William Allen Young (born January 24, 1954) is an American actor best known for his role as Frank Mitchell on UPN's "Moesha" and directing a few episodes of the show, and made a guest appearance on UPN's" The Parkers" as Frank Mitchell.
 His other television credits include "The Day After", "Matlock", "Babylon 5", CBS's "JAG", "Knots Landing", "The Jeffersons", and "The Women of Brewster Place", among other shows.
 He portrayed a recurring character on CBS's "" and a different recurring character on CBS's "".
 William currently plays Dr. Rollie Guthrie on the CBS medical drama "Code Black".
Brendan Jacob Joel Fehr (born October 29, 1977) is a Canadian film and television actor, perhaps best known for portraying Michael Guerin in the WB television series Roswell, and for portraying Laboratory Tech in .
 In 2008, Fehr won a Gemini Award for "Hottest Canadian Male TV Star".
 Brendan currently plays Dr. Drew Alister on the NBC drama The Night Shift.
Dana Snyder (born November 14, 1973) is an American stand-up comedian, actor, producer, and voice actor.
 He is known for voicing Master Shake on "Aqua Teen Hunger Force" and Granny Cuyler on "Squidbillies".
 He currently plays Dr. Colosso on Nickelodeon's comedy "The Thundermans".
Ethan Rains (born 1981 in Tehran, Iran) is an Iranian-American actor, best known for his portrayal of Dr. Leo Julian on the second season of SOAPnet's "", a 13-episode prime time spin-off of the ABC daytime soap opera "General Hospital".
 In December 2011, he guest starred on "Days of Our Lives" as a bad guy in a storyline involving illegal internet gambling.

Question: What is the actor who plays Dr. Leo Szilard best known for?
Answer: his role on the NBC television series, "L.A. Law"