The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Shooter (Genre) (41 members)
- Side-scroller (Genre) (3 members)
- SideQuest Studios (Developer) (4 members)
- Sideline Amusements (Developer) (1 member)
- Sidhe (Developer) (5 members)
- Sidhe (Publisher) (1 member)
- Sidhe Interactive (Developer) (1 member)
- Sierra Entertainment (Publisher) (1 member)
- Sigma Team (Developer) (1 member)
- Silence all logs: On (Config) (5 members)
- Silent Hill (Series) (3 members)
- Silicon Knights (Developer) (1 member)
- Silicon Studio (Developer) (2 members)
- SilverStar (Developer) (2 members)
- SilverStar (Publisher) (3 members)
- Silverball Studios (Developer) (1 member)
- Simulation (Genre) (16 members)
- SingStar (Series) (28 members)
- Single-player (Game mode) (1,471 members)
- Size Five Games (Developer) (1 member)