The Ithaca 37 bottomloading pump shotgun is easily one of the most well liked and successful shotgun designs ever conceived. A thoroughbred gun, it came from the consolidation of patents and revisions attributed to legendary firearms designers John Browning and John Pedersen. The Ithaca combined a clever and unique design with good manufacturing, sturdy materials and of course, good timing to become a roaring success- indeed, so successful, it made all other Ithaca Gun Company products irrelevant, and the weapon is known only as "Ithaca" (the company only sells one product that isn't a 37 derivative).
The Ithaca 37's main "gimmick" is it's loading and ejection *port*. Not "ports", just port. It only has one. Shells are loaded and ejected from the bottom of the receiver during a normal pump stroke. This clever design lends the 37 a number of advantages; for one, it's friendly to both left and right hand shooters. It is simple to mount a scope on; dirt and other potential hazards only have one possible point of entry. It also looks cool, which paired with the gun's excellent manufacturing quality means it's been in a huge number of movies; from Terminator to Aliens to The Thing and Death Wish, the Ithaca is a regular in cinema and probably always will be.