A killer game or system seller is a kind of game that makes a consumer want to purchase a console primarily for that game. It's often because of a significant leap forward in graphics, but can also be because a game offers something unique, never seen before, critical acclaim, or appeals to an entirely new audience. Companies try to put out at least one system seller during the launch of a console in order to convince people to purchase it. In the case of PC gaming, a gamer may spend money upgrading computer parts to play the game at high settings.
Exclusives tend to be better system sellers than cross-platform games. Additionally, a sequel on a new console is usually a big system seller (e.g. Halo 3 on Xbox 360). However, a sequel released on the original game's console may not generate higher system sales, because gamers who wanted that type of game will have already purchased the console for the original (e.g. Halo 2 on Xbox).
Typically, a good game will cause some sort of hardware bump, but only a killer game provides a large and sustained system boost. A killer game is nearly always a best seller, but a best selling game is not always a system seller.
- Pokémon X & Y and Sun & Moon - drove massive spikes in sales for the 3DS. Sun & Moon particularly raised 3DS sales to stay steady compared to previous years despite the handheld being so old at that point
- Splatoon - In Japan, the title kept the Wii U from abysmal sales. Its sequel has become one of the best
- Grand Theft Auto V - Despite releasing earlier on the last generation, the game has sold continuing to be on the Top 10 of the NPD every year since launch
- Halo 5
- The Legend of Zelda: Breath of the Wild - Sales of the Game actually exceeded the sales of the Console itself
- PlayerUnknown's Battlegrounds - As an Xbox exclusive, it pushed sales of the Xbox One alongside with Xbox One X in Winter 2017.
- God of War 2018
- Wii Sports
- Halo 3 - 50% increased Xbox 360 sales in the United States
- Gears of War & Gears of War 2
- Wii Fit
- GTA IV - surprisingly not a big system seller even though it was highly anticipated and earned outstanding reviews
- The Legend of Zelda: Twilight Princess
- Halo & Halo 2
- God of War & God of War 2
- Grand Theft Auto III
- Final Fantasy X
- Super Mario 64
- Legend of Zelda: Ocarina of Time
- Tomb Raider
- Gran turismo
- Resident Evil 2
- Super Mario World (SNES)
- Pac-Man (Atari)
- Super Mario Bros. (NES)
- Tetris (Game Boy)
- Brain Training (NDS)
- Pokemon (Game Boy)
- Sonic The Hedgehog (Mega Drive)
- Half-Life 1 & 2