Aside from the default free games (http://www.gog.com/en/catalogue/?price=free), which games have been given away as a part of special promos?

For example:

Realms of Arkania 1+2 - September 2012 - survey
Fallout - April 2012 - spring conference
Empire Earth - December 2011 - holiday gift
Broken Sword 1 - September 2011 - 6 million downloads

Super awesome of GOG to do these giveaways for customers. I'm curious since I sadly didn't become an active member of the community until early last year.

Jagged Alliance: Deadly Games - Apolgies
Tex Murphy 1+2 - Christmas 2009 (?)

/e: Ninja'd :(

Jagged Alliance Deadly Games (when GoG left beta)
Master of Orion 1+2 / Realms of Arkania 1+2 in limited numbers during the Christmas stuff last year I think
Tex Murphy 1+2 at some point, I forget when exactly

Martian Memorandum and Mean Streets were given out on Christmas 2009 (I think)
Jagged Alliance: Deadly Games was a consolation prize for the infamous PR stunt of September 2010.

Nevermind, I wanted to edit :D

I think we already covered them all?

GOG gave me my Planescape Torment and Thief Gold for free, nyah :D
...for winning a guessing game and a drawing thing.

Does Witcher and Machinarium count for the Botanicula...incident?

They weren't effectively free since you had to have pre-ordered Botanicula in order to receive them (which was still an extremely customer-friendly move by GOG).

But I think the OP is asking about games that were given out free to anybody, without being tied another purchase.

Thanks, everyone.

And thank you to GOG!

I know I had The Witcher for free before the Botanicula pre-order thing...was that ever given away before that? Says purchased May 10, 2011. I don't seem to have my receipt in my e-mail anymore, which suggests it was just put on the shelf.