The Marx Brothers - Chico, Harpo and Groucho - have become immortal with their irresistible delight in turning the rational world on its head and exposing its hypocrisy and pomposity. TCM presents the quintet of hilarious romps the boys made at MGM. A Night at the Opera (1935) and A Day at the Races (1937), their first films for that studio and the ones overseen by visionary production executive Irving Thalberg, became two of the brothers' biggest hits. (No less an authority than Groucho considered Opera the best of all Marx Bros. movies.) At the Circus (1939) spotlights the screen's most unlikely ongoing romance - between Groucho and character actress Margaret Dumont, who gladly suffers every indignity he heaps upon her imposing person. Go West (1941) finds the boys as unlikely buckaroos, while The Big Store (1941), their final MGM outing, allows them to run amok in a department store. -written by Roger Fristoe LIST OF FILMS 1 Tuesday 8:00 PM   A Night at the Opera (1935) Three zanies turn an operatic performance into chaos in their efforts to promote their protégé’s romance with the leading lady. The Marx Brothers, Allan Jones, Kitty Carlisle. D: Sam Wood. BW 92m. CC 10:00 PM   A Day at the Races (1937) A group of zanies tries to save a pretty girl’s sanitarium. The Marx Bros., Allan Jones, Maureen O’Sullivan. D: Sam Wood. BW 110m. CC 12:00 AM   At the Circus (1939) The Marx Bros. team up to keep a circus from going bankrupt. The Marx Bros., Margaret Dumont, Eve Arden. D: Edward Buzzell. BW 87m. 1:30 AM   Go West (1940) Three zanies tackle outlaws and Indians when they head westward. The Marx Bros., John Carroll, Diana Lewis. D: Edward Buzzell. BW 81m. 3:00 AM   The Big Store (1941) A detective and his zany pals take over a failing department store. The Marx Bros., Tony Martin, Margaret Dumont. D: Charles Reisner. BW 84m. CC