Z! I had forgotten completely about that. I had used an Evergreen upgrade chip to make my 486SX/25 a DX4/100 in order to play that one!

blade runner
dune
ssi gold box
skies of arcadia
record of lodoss war
and
moog song producer for c64
oh man Deus Ex I need to play and don't want to bother with Steam because of offline mode being unavailable at times so PLEASE!
also X-Com also on Steam but want here instead.

System shock 1+2
Deus Ex
Sam and Max: Hit the road
Rayman 1+2
X-Com series
Full throtle
Day of the tenticle
Thief 1+2
Dungeon Keeper 1+2
Grim Fandango
Alone in the dark (1992)

Actually both of these games are free downloads at the moment(From wikipedia)

Monkey Island 1 & 2

Since we have soon some console games, I like to ADVAAAAAAAAANCE my list
PC
all Mechner games
Prince of Persia Warrior Within
Splinter Cell 1-3
Rayman 1-3
Metal Gear Solid 1&2
Devil May Cry 3
Grim Fandango
Gods
Heart Of Darkness
Jazz Jackrabbit 2
Magic Carpet
No One Lives Forever
NOX
Omikron
Pathologic
Severance: Blade of Darkness
The Chronicles of Riddick: Escape from Butcher Bay
Thief Series
Toonstruck
Vampire: The Masquerade – Bloodlines
SILVER
Resident Evil 1-4
Silent Hill 1-4
Max Payne 1&2
American Mcgee's Alice
System Shock 1&2
Call of Cthulhu: Dark Corners of the world
All old LucasArt games(LOOM)
Some Tomb Raider games(fav: Legend and Anniversary)
Fahrenheit
Darkness Within
Still Life 1&2
Penumbra Trilogy
Cryostasis
The Typing of the Dead
SuperNintendo:
Donkey Kong Country 1&2
Prince of Persia original
Super Metroid Prime
Earthbound
Yoshi's Island
Soul Blazer
Illusion of Gaia
Terranigma
Metal Max Returns
all Squaresoft games, all of them
Parodius
Pocky&Rocky 1&2
Contra III
Castlevania
Doom
Sailor Moon: Another Story
Tales of Phantasia
Zombies ate my neighbours
BATTLETOADS
Lost Vikings
Magical Pop'n
Nintendo 64
Banjo Kazooie&Tooie
Blast Corps
Chameleon Twist
Conker's Bad Fur Day
Doom 64
Gex 64
GoldenEye 007
Zelda: OoT&MM
Mieschief Makers(FUCK YES)
Perfect Dark
Sin & Punishment
Turok 1-2
Dreamcast
Elemental Gimmick Gear
Grandia II
Ikaruga
Jet Grind Radio
Ooga Booga
Power Stone 2
Legacy of Kain: Soul Reaver (OH YEAAAAH)
Quake III Arena
Rayman 2
Resident Evil: Code Veronica
ReZ
SHENMUE
SHENMUE 2
Skies of Arcadia
Soul Calibur
Sonic Adventure(terrible angle level 8( )
Sword of the Berserk: Guts Rage

Please, do not quote me unless you have something relevant to just me.

Here's my short list:
Crusader: no remorse
Crusader: no regret
Wing Commander series
Dune series
X-Wing series (particularly TIE Fighter and X vs T) (though I suppose it's pointless to even ask for Lucasarts games)
Mantis (old Origin spaceflight sim)
Demon Stalkers (old Micro Forte Gauntlet clone)
Earthsiege/Starsiege
Missionforce: Cyberstorm (and sequel)
Zork
Planetfall
Command & Conquer series would make my list, but turns out you can get them free from the publisher (original recipe won't install in a 64-bit environment, but we can't have everything).
Half of these are games I own and can't play anymore because new hardware and operating systems won't play nice.
PS I was super happy to see the Jagged Alliance series, as well as Descent and Castles.

Wizards & Warriors 2000

Thief: The Dark Project
Started a new genre of FPS games, all while managing to be one of the best games, and still is. Sadly, it's hard to get working on modern systems :(

Only listed games which I don't have:
Catacombs series (one of the very first FPSs)
Cosmo's Cosmic Adventure
Duke Nukem 1 e 2
Dune II: Battle for Arrakis
Dungeon Keeper 1
Hocus Pocus
Jill of the Jungle series
F-15 Strike Eagle II e III (from Microprose)
Secret Agent
SSI Gold Box series
Strife
Stunts
System Shock 1 e 2
The Wheel of Time
Total Annihilation (including the add-ons)
Transport Tycoon Deluxe
Ultima series (including Ultima Underworld and Worlds of Ultima)
Warcraft: Orcs and Humans
Wasteland (the spiritual ancestral of Fallout series)
Witchaven 1 e 2
Zork series

Whatever happened to Apogee? They showed up with a few games and then disappeared again. I can see it being tricky to figure out how to fit their older catalogue into GOG's price points, but I'd pay $6 for Raptor. I'd pay the same for Duke 1+2 together, if I didn't already own them.
That goes for Epic, too. Bring me Zone 66, and you will all be my personal heroes.

They sell their old games in the official company's site, the majority of them for $5.99, but i prefire buy them at GOG

While these games aren't terribly old I'd love to see Anachronox and Omikron: The Nomad Soul on here. Especially Anachronox being on of the greatest story driven RPGs I've ever played.

I would love to see Freelancer on gog.com. Great game, but no place to get it from for a fair price.
Two other games, that would simply be awesome: Dungeon Keeper and/or Dungeon Keeper 2. There is almost no other game, where you can be as mean as you want and get rewarded for it.