Here's a quick list of additions/corrections
Roleplaying Games:
- If Fallout 3 has made the grade Fallout 1&2 should definately be on there.
- Neverwinter nights wasn't awful so yeah. NWN1? No no no. Crapfest.
- Morrowind!
Adventure:
- Grim Fandango
- Full Throttle
- Day of the Tentacle
- Sam & Max hit the road.
- Flight of the Amazon Queen
- Dreamfall (TLJ2)
Horror:
- Silent Hill 2
- Realms of the Haunting
Racing:
- Trackmania United
Online Shooters
- How is BFBC2 up there and BF2 isn't?
- Joint Ops: Typhoon Rising
- Planetside
Turn Based Strategy
- Colonization (The original)
- UFO: Enemy Unknown
- Jagged Alliance 2
RTS:
- Dawn of War 1 and expansions
- How are HOI3 and Tropico in the Medieval RTS section. Neither are Medieval in setting and Tropico isn't an RTS! More to the point, where's Medieval Total War II?
Space Sim:
- Tie Fighter, X-wing and TF vs XW
Puzzle Games:
- Plants vs Zombies
- Peggle
- Puzzle Quest
Free Games:
- Dwarf Fortress
- N
- Soldat
- Notrium
- Clonk Endeavour
- Babylon 5: I've Found Her
- Sandbox of God
- Titans of Steel
Misc:
- Sim City 4
- Dungeon Keeper 2
- Rollercoaster Tycoon 2
- Transport Tycoon (OpenTTD)
Probably more but that's a start