This could easily be considered THE funniest movie if not as funny as any movie Michael Keaton has ever been in, including, Mr. Mom, Beetlejuice, Multiplicity, and probably even funnier than Johnny Dangerously (because Dangerously is intended to be pure slapstick and black humor COMEDY all the way). Whereas Night Shift is a parody and shows some pretense towards the normal but abnormalities of living in a big city, yet does so with pure improvised humor, the type that leaves you rolling on the floor laughing literally so, by the movies end. Perhaps Ron Howard's best Comedy he ever directed as well. If you need a guaranteed night of hard laughter, definitely rent or buy this movie. It can still occasionally to rarely be found in VHS sale racks, and was remastered for DVD. Definitely one of my favorite comedies. This movie and Keaton's role as the bumbling fumbling crazy but serious idiot makes this movie what it is, while Henry Winkler and Shelly Long attempt to balance this hilarious riot comedy with some serious sides of what is a attempt of living a normal life, but infiltrated with Keaton's wit, (which is as sharp and funny spontaneously as any Robin Williams stand up comedy has ever been). Keaton at his best, while his character is intensely amped up and nuts but serious. Keaton's character, Billy Blazejowski is the new hire in the Night Shift at the local morgue, a apprentice to the withdrawn surrendered Winkler. Blazejowski always carries around a mini tape recorder to capture his moments of brilliance, as he often comes up with inventions one after another. For example, at one point on his way out the door, he stops due to a brilliant plan for a invention and speaks into his voice recorder. New invention, feed Tuna mayonnaise, that way you already have Tuna Salad, boy would that save a lot of work! Kevin Costner's little role in this movie is not even worth mentioning, as he perhaps is on screen for 1 or 2 minutes, and this role could of been played by anyone. Costner's role was not cast with anyone special in mind. However, perhaps only Robin Williams is the only other actor who could of fulfilled Keaton's role, with the genius spontaneity of comedy. This movie was during a period in Keaton's life when he was only known for his comedy, and he definitely peaked with it here. However being the great actor he is, and like so few are unable to (exception being Robin Williams, again), was gifted enough to break away from the stereotypical nut ball comedian, by performing in serious roles with brilliance, later on in his career. This is a real sign of a great actor, who can float between a wide diverse number of different roles, from comedy, to serious drama, to Super Hero, and wicked criminal, to any serious drama and horror characters. Without doubt a 10 rating, and a genius by the Director Ron Howard, and lead actors, mainly Keaton.