The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- The Odd Gentlemen (Developer) (1 member)
- The Price is Right (Series) (2 members)
- The Quantum Astrophysicists Guild (Developer) (1 member)
- The Quantum Astrophysicists Guild (Publisher) (1 member)
- The Simpsons (Series) (1 member)
- The Sims (Series) (3 members)
- The Voice (Series) (1 member)
- The Walking Dead (Series) (4 members)
- The Workshop (Developer) (1 member)
- Third-person shooter (Genre) (78 members)
- TickTock Games (Developer) (1 member)
- Tiger Hill Entertainment (Developer) (1 member)
- Tigon Studios (Developer) (2 members)
- TikGames (Developer) (4 members)
- TikGames (Publisher) (5 members)
- Tiki Games (Developer) (1 member)
- Tiki Games (Publisher) (1 member)
- TimeGate Studios (Developer) (2 members)
- TimeGate Studios (Publisher) (2 members)
- Time Crisis (Series) (2 members)
- Timeline Interactive (Developer) (1 member)
- Titan Studios (Developer) (1 member)
- ToeJam and Earl (Series) (2 members)
- Tom Clancy's Ghost Recon (Series) (2 members)
- Tom Clancy's H.A.W.X (Series) (2 members)
- Tom Clancy's Rainbow Six (Series) (1 member)
- Tom Clancy's Splinter Cell (Series) (3 members)
- Tomb Raider (Series) (4 members)
- Tony Hawk's (Series) (6 members)
- Top-down shooter (Genre) (5 members)
- TopWare Interactive (Publisher) (3 members)
- Top Spin (Series) (2 members)
- Topware Interactive (Publisher) (1 member)
- Torn Banner Studios (Developer) (1 member)
- Torn Banner Studios (Publisher) (1 member)
- Torus Games (Developer) (4 members)
- Torus Games (Publisher) (1 member)
- Tose (Developer) (1 member)
- Tower defense (Genre) (15 members)
- Toxic Games (Developer) (1 member)
- Toxic Games (Publisher) (1 member)
- Toy Story (Series) (1 member)
- Toybox Inc. (Developer) (1 member)
- Toys for Bob (Developer) (4 members)
- Tozai Games (Publisher) (3 members)
- Tragnarion Studios (Developer) (1 member)
- Trails (Series) (1 member)
- Train Simulator (Genre) (2 members)
- Train Simulator (Series) (2 members)
- Transformers (Series) (7 members)