While it wasn't the first, the NES Zapper is perhaps the most iconic light gun. The Zapper was first released in 1984 as the Beam Gun for the Famicom along with the game Wild Gunman. You may recognize the game from the Cafe 80s in Back to the Future II. In the scene (which was Elijah Wood's first on-screen appearance) the kids of 2015 were throughly unimpressed: "You have to use your hands? That's like a baby's toy!”
In 1985 the Zapper was released in North America, alongside the launch of the NES. The Zapper was included in the NES Action Set and came bundled with Duck Hunt.