Not really PC games but these titles laid out the foundation for later games.
Primarially text and vector graphic based games with simple input and simple goals.
1981 - 1984
CGA Era games, as well as text
1984 - 1987
1987 - 1992
Multiplayer games typically relied on serial communications or a modem to a BBS type server.
1992 - 1996
VGA Era Games, Rollout of CD-ROM titles heavy on live action movies
Networked multiplayer became commonplace through IPX / SPX
1996 - 1998
First generation 3D Titles, primarially Glide and OpenGL.
Internet enabled games became commonplace through UDP / TCP, including first massivly multiplayer.
1998 - 2000
Games relying on DirectX became commonplace, Glide started phasing out.