IGN just release their top 100 games of all time ( 2007 editions ). Since I'm a PC gamer (95% of my gaming time was on PC), I'm trying to grab most major PC games (which I'm really enjoying from time to time) from the IGN 2007 list:

IGN top 100 of all time (2007 edition)

http://top100.ign.com/2007/

98. Quake II (id software) 1997
93. Ultima VII: The Black Gate (Origin System) 1992
89. Alone in the Dark (Interplay) 1992
84. Maniac Mansion: Day of the Tentacle (LucasArts) 1993
83. World of Warcraft (Blizzard) 2004
82. Syndicate (Bullfrog / EA) 1993
74. Sam & Max Hit the Road (LucasArts) 1993
72. MechWarrior 2 (Activision) 1996
71. Planescape: Torment (Blackisle / Interplay) 1999
65. Thief II: The Metal Age (Looking Glass / Eidos) 2000
62. Wolfenstein 3-D (id software / Apogee) 1992
60. Prince of Persia (Broderbund) 1989
59. Command & Conquer: Red Alert (Westwood / Virgin) 1996
52. Dune II: The Building of a Dynasty (Westwood / Virgin)
43. Baldur's Gate II: Shadows of Amn (BioWare / Interplay) 2000
34. Deus Ex (Ion Storm / Eidos) 2000
33. Fallout (Interplay) 1997
28. Warcraft II: Tides of Darkness (Blizzard) 1995
27. Star Wars Knights of the Old Republic (BioWare / LucasArt) 2003
26. Half-Life (Valve/Sierra) 1998
25. SimCity 2000 (Maxis) 1996
22. System Shock 2 (Looking Glass / EA) 1999
21. X-COM: UFO Defense (MPS lab/Microprose) 1993
19. Doom (id software) 1993
12. Star Wars: TIE Fighter (Collector's CD-ROM) (LucasArt) 1995
11. StarCraft (Blizzard) 1998
6. Half-Life 2 (Valve / Vivendi Games) 2004
3. Civilization II (Microprose) 1996

and just for reference 

(2006 edition)
# 097 // Warcraft III: Reign of Chaos (Blizzard) 2002
# 089 // Half-Life (Valve / Sierra) 1998
# 079 // Max Payne 2: The Fall of Max Payne (Remedy / Rockstar) 2003
# 065 // StarCraft (Blizzard) 1998
# 063 // Call of Duty (Infinity Ward / Activision) 2003
# 061 // Unreal Tournament 2004 (EPIC / Atari) 2004
# 057 // The Elder Scrolls IV: Oblivion (Bethesda softworks) 2006
# 043 // Jade Empire (Bioware/Microsoft) 2005
# 023 // Star Wars Knights of the Old Republic (Bioware / LucasArts) 2003
# 013 // Half-Life 2 (Valve / Vivendi Games) 2004

(2005 edition)
# 099 // Ultima Underworld: The Stygian Abyss (Origin System) 1991
# 093 // Quake II (id software) 1997
# 090 // Master of Orion (SimTex / MicroProse) 1993
# 089 // Alone in the Dark (Infogrames / Interplay) 1992
# 087 // Thief II: The Metal Age (Looking Glasses Studio / Eidos) 2000
# 085 // Prince of Persia (Broderbund) 1989
# 084 // Ultima VII: The Black Gate (Origin System) 1992
# 074 // Syndicate (Bullfrog / Electronic Arts) 1993
# 071 // Half-Life: Counter-Strike (Valve / Sierra) 2000
# 068 // Starsiege: Tribes (Dynamix / Sierra) 1998
# 066 // Homeworld (Relic / Sierra) 1999
# 065 // MechWarrior 2: 31st Century Combat (Activision) 1995
# 061 // Sam & Max Hit the Road (LucasArts) 1993
# 060 // Maniac Mansion: Day of the Tentacle (LucasArts) 1993
# 055 // Fallout (BlackIsle / Interplay) 1997
# 053 // Age of Empires II: The Age of Kings (Ensemble / Microsoft)1999
# 050 // Wing Comander II: Vengeance of the Kilrathi (Origin System) 1991
# 041 // System Shock 2 (Looking Glass / EA) 1999
# 039 // DOOM (id software) 1993
# 036 // Command & Conquer: Red Alert (Westwood / Virgin ) 1995
# 035 // Dune II: The Building of a Dynasty (Westwood / Virgin) 1992
# 031 // SimCity 2000 (Maxis) 1993
# 028 // Half-Life 2 (Valve / Vivendi) 2004
# 025 // Baldur's Gate II: Shadows of Amn (Bioware / Interplay) 2000
# 022 // Half-Life (Valve / Sierra) 1998
# 021 // Deus Ex (ION Storm / Eidos) 2000
# 012 // X-COM: UFO Defense (Mythos / Microprose) 1994
# 009 // Star Wars: TIE Fighter Collector's CD-ROM (LucasArts) 1995
# 007 // StarCraft (Blizzard) 1997
# 004 // Sid Meier's Civilization II (Microprose) 1996

While I may not satisfy about the game list from their collection, I do agree that most PC games list on their collection are truely masterpieces of all time (at least, in my own opinion )

i like HL2 the most

IGn's list's still crap because it didn't have a Diablo game or Morrowind or Max Payne on the list.

hell yeah Civilization II owns. I just think Civ4 could have appeared as well. and even though I'm not a fan, The Sims should be mentioned too... 

and from the top 10, I own the first 6 (Super Mario Bros as the Mario All-Stars version), and only haven't played RE4 yet.

I think Civ4 was released too late to be on the list.

No offense but I hate top games lists for systems. There is such a wide breadth of solid games that making a list just doesn't seem right. At least, don't make an ordered list and break it down by genre :).

Quake 2 is awesome, I would highly suggest everyone playing that. Warcraft 3 and Starcraft are great too.

Ahh Quake 2, the birth of the railgun, and consequently a new breed of whiner.

I'm a little surprised Planescape didn't rate higher. I think it still has one of the best RPG stories ever.

DON'T TRUST THE SKULL

This is the private list of my own game of all times -- please note, you may only find PC games here because I mostly play game on my own desktop for years (even I have a SFC / PC-E and after couple years finally a Wii)
. I try to divide the my favorite games with different genres, hope it helps. Oh and one more thing: I just place them with random order.

RPG:

System Shock (Looking Glass Studio / Origin System)

System Shock 2(Looking Glass Studio / EA) 

Ultima Underworld (Looking Glass Studio / Origin System) 

Eye of Beholder (Westwood / SSI) 

Some Might and Magic Series (maybe III, VI, and so on)

Wizardy VII ( Sir-Tech )

Ultima VI ( Origin System)

Dark Sun (SSI)

Icewind Dale (Black Isle / Interplay)

Baldur's Gate (BioWare / Interplay)

Baldur's Gate II (BioWare / Interplay)

NeverWinter Night ( BioWare / Atari )

The Witcher ( CDPROJEKET / Atari ) 

Flight / Shooting Game:

X-Wing (LucasArts)

TIE Fighter (LucasArts)

Falcon 3.0 (Spectrum Holobyte)

FreeSpace 2 (Interplay)

Wing Commander 3 (or 2?) (Origin System)

Comanche (NovaLogic) 

Magic Carpet ( Bullfrog / EA) 

Strategy (non-real time)

Populous (Bullfrog / EA)

Populous II (Bullfrog / EA)

Master of Orion (Microprose)

Master of Orion II (Microprose)

Master of Orion III (Atari) 

Master of Magic (Microprose)

Civilization IV (2k)

X-COM: UFO / Enemy Unknown (Microprose)

...... well, I guess I better take a break and do the real-time strengy / FPS game at tomorrow (sorry I'm not even an advanture / sport / racing / puzzle type fanboy, so there's no those games :p ) 

The list is crap cause Killzone isn't on it.