I just mention some examples:

F.E.A.R. series: F.E.A.R. 3
Fallout series: 3, New Vegas, 4
Red Faction series: Guerrilla, Armageddon
Sacred series: Sacred Citadel, Sacred 3

I don't see any reasons why publishers don't release those games on GOG. Technical issues? Legal issues? Is it TOO SOON to release DRM-free version? Or what?

A mix of all the above, I'd guess. Legal issues especially, must be royal pain and maybe the biggest problem of all.

I have no answer, but i would love to know that to, i want to try FEAR 3 and harvest aliens in Red Faction Armageddon...
That can not be publisher problem, because FEAR 3 has been released by the same who released the 1 and 2. Yeah, i think you're right when you say that "it's too soon to release DRM-free version"...
I never heard of Sacred Citadel though...


EDIT : Damn, nobody answer for 50 minutes and suddenly 3 people post their messages...

Because the publisher doesn't want to. Either they don't want to rip out other elements or they just don't feel the need to atm, or they plan to, just not now.

F.E.A.R. 3 uses Steamworks (I think) and is a predominantly co-op game. (It sucks ass too). So they probably don't feel like ripping that out.

Fallout 3 and New Vegas could potentially come here and probably will, but you just have to deal with the fact that GOG and DRM-Free versions are not seen as high priority.

Red Faction Guerrilla switched from GFWL to Steamworks, and I'm assuming Armageddon uses Steamworks as well.

I don't know about Sacred 3 but I heard it's very, very bad.

Yeah, I could even understand if GOG rejected it. XD

And I say that as someone who doesn't care about any continuity in the Sacred series and as someone who can have fun with mediocre games as well. I was ready to play it as an independent so-so hack and slash brawler, but the humor is so terrible and forced, and the gameplay so rail-roaded and boring, I still couldn't endure it.

Just forget that this game exists and play Victor Vran instead, or vote for Marlow Briggs and the Mask of Death on the wishlist. Both aren't among the greatest games, but they're still leagues above Sacred 3. And occasionally funny.

By the way, this is already the subject of a handy reference thread.

Sacred 3 and Citadel doesn't cover the Good in Good Old Games, hopefully that's the reason at least. :D

The others it's likely a deal breaker with DRM-free or perhaps some pesky law that blocks a potential deal.

I sometimes have this image of the GOG staff banging their heads on the walls of the office, muttering "why did we ever call it that? People are never going to let that fucking name go!"

I'm hoping for PixelJunk Shooters 2... Which was on PS3 I think.

We just got Arcania and Fall of Setarrif. Can't be worse...

The Myst series is also strangely incomplete.
Myst and Riven (Myst 2) are on here, and so are Myst 5 and Uru.
Myst 3 and 4 though? Nope. A real shame! I never got to play those two, and I felt bad to just jump into Myst 5 without having played them.

At this point though? I might just bite the bullet and do it.

There are quite a few reasons for series being incomplete here. Some of them are:

1) There is no DRM-Free build and the publisher isn't willing yet to spend their time/money to create one (Red Faction: Guerrilla)
2) No particular interest from a developer/publisher in bringing their newer stuff here (Deus Ex: Human Revolution)
3) Sequel contains licensed content (Pirates of the Carribean)
4) The rights to the sequel(s) are divided between companies who have been unable to find a common ground (Myst 3 and 4)
5) GOG considers the sequel low priority material (Spellforce 2: Faith in Destiny. Probably why it also took ages to bring Arcania here)
6) GOG hasn't been able to get the game to run well (though given some of their releases like the Warhammer series, I'm skeptical about the last one)

Either a game outright sucks (anything after Sacred 2 in that series)
The publisher feels they can still squeeze $$$$ even sans DRM free (most of the above)
GOG may not find a given game is a priority (FO3, FONV especially would be quite desirable here. F.E.A.R is actually an OK game for what it is -- it can be done single player (never mind the earlier co op comment - it isnt required))

I don't know.. I always thought it was a great name and while they began to diversify into indies and at least the occasional AAA game, all games eventually turns old and given it's a technological medium that is changing, games grow old fast so essentially I see GOG more of a commercialized archive for games.

As someone who never liked the Gothic games to begin with I wouldn't have high expectations and I thought Sacred 1+2 were one of the best ARPG out there. Sacred 3 and Citadel are the worst kind of cash-grab arcady, hyped-with-no-substance games I've seen in a while. Granted, I watched early gameplay footage before I played either so it's not like I was that disappointed.

That said, it's interesting that they acquired those games and when you look at reviews people aren't very positive about them. Didn't GOG design some market research before acquiring them or did they just grab them because the deal was cheap and they hoped to sell at least a few copies? If it's the former, they lack marketing staff and if it's the latter it seems they've entered a tough area to get out of. Less and less classics are going to be available as they acquire the good ones, only the hard ones are going to be stuck in legal limbo which will likely be too expensive to bother with unless there are no other (very) old games left.