Older pc games.

-Mafia
-GTA London 61' & 69', GTA1 & 2
-Colin McRae series
-Dune 2000

The original (best) version of Loom. ...Steam only has the voice-acted version, which is missing some content because they had to cut it to fit the voices on a CD.

Callahan's Crosstime Saloon. Classic point'n'click adventure, one of the funniest games I've ever played.

Edit: Also Master of Magic.

One Must Fall: 2097

View attached image.

Master of Orion 2
Master of Magic
Betrayal at Krondor

Mercenaries

If I don't see Battlefront II or SW Republic Commando on that list....

Neverwinter Nights 1 & 2
Planescape: Torment
Arcanum
Betrayal at Krondor
Diablo 1 & 2
Urban Assault
Battlezone 1 & 2 (though, the first game is being remade, so I guess we should see that on Steam at some point. Yay!)
Mechwarrior series
Mechcommander 1 & 2
Marathon Trilogy
Monster Truck Madness 2 (This game is amazingly fun to play with others)

I know there are a lot more that I would like to see, but I can't think of them right now. =P

Blood omen: Legacy of kain original

Emperor: Rise of the Middle Kingdom (the last 2D city builder from Sierra; they released it up until Zeus+Poseidon, but not the last entry).

Wolfenstein: Enemy Territory
Halo 2
Myst(entire series)
And obviously games like Battlefield 3, and other games that EA restricts to origin.

Croc 1 - Croc 2

Pinball Fantasies was a good one to make championships on family :D

Would be really nice to have a reamstered version :)

View attached image.

I think Steam should just stay away from the old games because they don't care about whether they'll work on modern PC's or not, they just release anything. GOG on the other hand does its best to make the games playable.

Anyway I'd love to play Powerslave/Exhumed again. But only with higher resolution sprites and mouse-look feature, so we'd need someone to work on it a bit, like what happened with Strife.

Dreamweb!

That game had an amazing story and great atmosphere. It was way more grown up than other games of its time. loved it.

Does Heavy Metal F.A.K.K. 2 have a scene when Julie sucks and alien? Like in animated movie? ;)

As for old games, they're better on GOG, they at least put some effort to make them compatible with newer os systems.

BTW, anyone remember old rts that had 4 races. Snakelike purple masters, red 3 leg enforcers, kinda treelike slaves and 4th mystic race?

All i remember from this game that Snakes had unit on snails that looked bit like bikes ;)

Oh and there were hero units too, and ugrades.

Graphics kinda like warcraft 2

Edit2
NVM, all i had to do was to check list of old rts games.

It was War Wind.

Master of Magic.
well, not actually, since i have the reboot.

but maybe dune 2?

dune

Not so old the first Test Drive Unlimited, Evil Dead: Regeneration, Freelancer, first Halo, Myst 3-4, Neverhood, Splinter Cell: Pandora Tomorrow and first Battlefront. This is only few games that i remembered now.

Zoo Tycoon, Empire Earth, Anno 1503.

Colin McRae Rally 2.0. I had so much fun with that game, but I can't find it anymore not even in 2nd hand stores
The newer versions just aren't as good as that one. I just loved it, mainly because it wasn't as realistic as the ones that came after it I tried Dirt 3 but it is almost unplayable on pc, because of the oversensitive controls, even with a controller

In my personal list.

Sim City 3000 because it was first city builder i ever played.
Warcraft 1 and 2, i not sure if they are on BN to download now.
Warcraft 3 on steam because is huge modbase, but could be nice integrate game with steamworks.
Dune 2000 one of my fav RTS games, as long with RA1.
Need For Speed Underground 1 & 2 best games of the series, well first Most Wanted was also cool. But after Carbon i don't think so.
Heroes Of Might & Magic 3 Non HD and 4 on steam.

Metal Gear Solid 1 and 2.

Soldier of fortune
No one lives forever
Arcanum
Blood omen