Duck Hunt first debuted as an arcade game in 1984 before the release of the Nintendo Entertainment System. Duck Hunt machines ran on the Nintendo Vs. Unisystem hardware.
The arcade version of Duck Hunt was almost identical to the version later made for the NES. The main difference was that the "Skeet Shoot" round was a bonus game instead of an alternate play option (actually there were not any player selectable options at all).
Duck Hunt machines were most often converted Donkey Kong cabinets (the Nintendo Vs. Unisystem was designed as a kit to retrofit the Donkey Kong series of games). You would rarely see one in any other cabinet, as this title requires a "Nintendo Compatible" monitor, and only a scant few games had that monitor. So you couldn't convert a non-Nintendo title without buying a new monitor, or doing some dodgy wiring that most game operators didn't want to deal with.
Dedicated Duck Hunt machines were produced in limited numbers. They came in a large cabinet that resembled two arcade games joined at an angle. These machines had two monitors and two control panels, but ran both of them off a single gameboard. One very strange feature was the hardware was capable of running two completely different titles simultaneously (arcade multi-tasking!), by plugging in a small ROM daughterboard into the Vs. motherboard.
Duck Hunt machines could be converted to Hogan's Alley or Wild Gunman by simply swapping the rom chips (or plugging in a daughterboard). They could also be converted to most other Vs. titles easily, but any other title requires a new control panel.
These Duck Hunt machines did not have much in the way of decoration, usually just a marquee which featured a cartoon scene of several ducks and your hunting dog in a pastoral setting (it is pretty cool looking, I have one, because there was a whole Duck Hunt kit up on eBay as separate components, and I bid on all of them, but only won the marquee).
Duck Hunt conversion kits and machines are still fairly common, although they are more expensive than most other Vs. titles. The cheapest way to get one is to buy a different Vs. game and then get a conversion kit.
A small note about the NES Duck Hunt. The cartridge containing Duck Hunt by itself was only made in limited numbers and has become quite rare today (although it is not very valuable). Finally, you actually "influenced" the duck's movement using the controller in port 1, as port 2 was where the zapper plugged in (this only works in "single duck" mode).