legacy of kain + soul reaver games (ill just cheat and count these all as one entry)
Warzone 2100
Ico
Shadow of the Collossus
Medievel 2 : Total War (tough choice between ths one and Rome)
Mass Effect
X-Com UFO Defense
Sins of a Solar Empire
World In Conflict
Men of War
Not sure if these are deffinitely the best of all time but they where the ones that stood out in my memmory when i went to write the list.

Obviously your rating may vary. I'm using the method the original poster did.
Fixed positions
---------------
1. Earthbound
2. The Witcher
3. Chrono Cross
4. Chrono Trigger
5. Planescape: Torment
6. Blade Runner
Interchangeable
---------------
-Final Fantasy VII
-Final Fantasy X
-Starcraft
-MOTHER 3

I don't think such a list exists. As time passes, my old favorites move up or completely fall off my list.
1. Final Fantasy
2. Mechwarrior
3. Diablo
4. Street Fighter
5. Quake
6. Wing Commander
7. Need For Speed
8. 3D Mario games
9. Tekken
10. Master of Orion 2 :-)

This is what I came up with. It's a rather odd list. I realised that there are a lot of DS games on it, actually.
1. Baldur's Gate series (first pc game I ever bought =) )
2. Psychonauts (just so many cool ideas!)
3. Etrian Odyssey (on DS, poured a lot of time in this one)
4. Lufia 2 (on SNES. first jrpg I ever played. One of the few I ever enjoyed)
5. Secret of Evermore (on SNES. reviled clone of Secret of Mana. I find it vastly superior. Awesome music)
6. The World Ends With You (on DS. Did a lot of new things and did them right)
7. Henry Hatsworth (on DS. In my opinion, the best platformer ever)
8. Shiren (on DS. The only roguelike game you'll ever need)
9. Cave Story (This one just made me feel happy playing it. Lots of fun)
10. Fallout series (I don't think I need to elaborate on this one)

my top 10 games ever is
10. manhunt
9. postal 2
8. diablo 2 (LOD)
7. Stronghold crusader
6. morrow wind
5. the witcher
4. need for speed carbon and most wanted
3. grand theft auto the series
2. titan quest imortal throne
1. elder scrolls 4 oblivion

NOTE: This order doesn't really denote quality. These games are all special in their own ways.
1. Half-Life series.
2. Golden Sun series.
3. Metroid series.
4. Legend of Zelda series.
5. Psychonauts.
6. Grim Fandango.
7. Fallout series.
8. Neverwinter Nights 1 (mostly for all the extra modules I found online).
9. The World Ends With You.
10. Baldur's Gate series.
11? Age of Empires 2.

In no particular order:
Jagged Alliance series
Fallout 1+2
Red Alert 1+2
X-Com: UFO Defense
Monkey Island 1+2
Civilization 2
Dune 2 (for the sole reason it gave birth to a genre)
Return to Castle Wolfenstein: Enemy Territory (my first online game and the 1st game that got me into a clan)
Call of Duty 4
Commandos 1+2

MORE WING COMMANDER. :P

I have never played sc2000 that much. played the shit out of SC the first one then there was break and when i got my hands on sc3000 i felt in love immediately.
got sc4 a year ago or so... didn't play it yet.

My list would be:
Quake
Quake 3
Duke3d
Carmageddon 1
Carmageddon 2
Tomb Raider 1
Tomb Raider 2
Max Payne 1
Serious Sam 1
Recoil
Man, sad to see that there is not 1 single newer game in that list, although Bioshock almost made it in, but didnt because I never actually replayed the game more than a 1/2 a time.
All of the above make the list bacause I played them all at least 3 times, and some even more than 3 times.

In no order:
Portal
Legend of Zelda: Ocarina of Time
Team Fortress 2
Psychonauts
Fallout
Freespace 2
Minesweeper
Bioshock
Half Life 2
Zeno Clash

I know it is knit picking but this is a list of Your Top 10 BEST Games of All Time.
So here is my personal list.
Tribes
Tribes 2 (This would be my all time favorite game hands down)
Homeworld
Homeworld Cataclysm
Command & Conquer Red Alert series
Ryzom
Civilization Series (Including Alpha Centauri)
Sword of the Stars plus Expansions
Space Empires IV
Space Quest/King's Quest Series

Picking 10 games is near enough impossible but sticking to PC games and in no particular order:-
1. Ultima Underworld
2. Pandora Directive
3. Gabriel Knight
4. Monkey Island 2
5. Wing Commander 4
6. The Longest Journey
7. Final Fantasy 7
8. X-Wing
9. Ultima 7
10. System Shock
The thing in common with most of this list is that I tend to go for story driven games. There's a lot of Origin games on there also. It's about time we saw some of these on GOG. Not long to wait for The Pandora Directive at least, which would always be in my top 10.

There was a similar thread before (I think it was 3 best games) but I'll participate.
I am not going put any order to them, ordered just as they come to mind.
And not to fill the list with Final Fantasies I will put the best ones together.
ADOM - There's more depth to the game than you can find after month of playing
Final Fantasy IV, V, VI, VII - The Best RPG's. Though the new ones are good, I just don't seem to like them so much.
Thief: The Dark Project - Garrett can steal anything. Just believe it.
X-com Apocalypse - The X-Com series is just awesome and I like Apocalypse the most.
Vagrant Story - The best not Final Fantasy RPG there is.
Fallout 1 and 2 - I think of these two as a single game, like part 1 and part 2. The third was, imo, a first person shooter.
Morrowind - The best of Elder Scrolls series. Easily.
Civilizations 4 - Best turn based strategy there is.
Company Of Heroes - Best real time strategy there is.
Hearts Of Iron 2 - There aren't many war simulation games out there, and HoI 2 is the shining star among them. Waiting for the third one like child in Christmas :3
Well, eleven games but who cares ;)