Here's what isn't on sale at all, according to GOG's overall game list -

A Golden Wake
Advent Rising
Age of Wonders
Age of Wonders 2 - The Wizard's Throne
Age of Wonders - Shadow Magic
Age of Wonders 3
Age of Wonders 3 - Golden Realms
Age of Wonders 3 - Deluxe Edition
Arx Fatalis
Baldur's Gate Enhanced Edition
Baldur's Gate 2 Enhanced Edition
Banner Saga
Bloodrayne
Bloodrayne 2
Broken Sword Director's Cut
Broken Sword 2 Remastered
Broken Sword 3 - The Sleeping Dragon
Broken Sword 4 - The Angel of Death
Broken Sword 5
Challenge of the Five Realms
Cosmo's Cosmic Adventure
Defender of the Crown
Democracy 3
Democracy 3 - Extremism
Democracy 3 - Social Engineering
Devil's Dare
Divinity - Original Sin
Divinity Original Sin - Source Hunter
Doorkickers
Dreamfall Chapters Season Pass
Dreamfall Chapters Season Pass Special Edition
Dreamfall Chapters Season Pass Special Edition Upgrade
Gabriel Knight - Sins of the Fathers 20th Anniversary Edition
Gangland
Gex
Gothic
Guacamelee Super Turbo Championship Edition
Halfway
Hatoful Boyfriend
Icewind Dale Enhanced Edition
Incredible Machine Mega Pack
Indiana Jones and the Fate of Atlantis
Knights of the Old Republic
Kromaia
Legend of Grimrock 2
Legend of Heroes - Trails in the Sky
Lovely Planet
Magicmaker
Magrunner - Dark Pulse
Mitsurugi Kamui Hikae
Octodad - Dadliest Catch
Outcast
Paper Sorcerer
Pier Solar and the Great Architects
Raiden 3 Digital Edition
Risk of Rain
Rocket Ranger (Emulated Amiga Edition)
Runaway - A Road Adventure
Runaway 2 - The Dream of the Turtle
Runaway 3 - A Twist of Fate
Sam and Max Hit The Road
Screencheat
Secret of Monkey Island Special Edition
Shadowgate
Shadowgate Special Edition
Shadowgate Special Edition Upgrade
Shovel Knight
Sir, You Are Being Hunted
Slender - The Arrival
Smugglers 5 Invasion
Space Run
Space Com
Starpoint Gemini 2
Steamworld Dig
Street Fighter Alpha 2
Super Time Force Ultra
Supreme Ruler 2010
Surgeon Simulator 2013
Surgeon Simulator Anniversary Edition
Tales of Maj'Eyal
Tales of Maj'Eyal - Ashes of Urh'Rok
The Vanishing of Ethan Carter
TIE Fighter Special Edition
Tri
Vangers
Wargame - European Escalation
Wasteland 2 Digital Classic Edition
Wasteland 2 Digital Deluxe Edition
Wasteland 2 Digital Deluxe Edition Upgrade
Where Is My Heart?
Wings (Emulated Amiga Edition)
Wings Remastered Edition
X-Wing Special Edition

Many thanks for the effort. Was wondering myself :)
Bugger was hoping for a discount on Shovel Knight and Starpoint Gemini 2 myself :D

Disciples: Sacred Lands Gold at 75% has been unlocked. Bad Mojo Redux is next.

Not a problem. Putting overcaffeination to use. (Also, kiss my ass, spellchecker. Doublechecked that one on Google.)

Argh, many of those are on my wishlist as well...

Has anyone tried that RTS game called Meridian: New World?

Yah. I had to go through mine manually to find which titles were on sale. Here's the titles I have uncovered so far, maybe we need another thread to list all the ones folks have found as discounted.

Always Sometimes Monsters (50%)
Conquest Of The New World (50%)
Crystal Caves (50%)
Darkstar One (50%)
Die By The Sword + Limb For Limb (50%)
Monster Bash (50%)
Neverending Nightmares (25%)
Quest For Infamy (50%)
Realms Of Chaos (50%)
Rise Of The Triad: Dark War (50%)
Secret Agent (50%)

Thanks for doing that! I was just starting to myself and you saved me a ton of time.
Interestingly it cover 90% of my wishlist. ;)

The bundle images are in the following format: http://www.gog.com/bundles/gogwebsitefallpromo/img/daily_deals/769472e32cc0cc8de9a1ab79d4167105.jpg
Changing the numbers to the correct one will bring an image, but guessing them is nearly impossible. Idea was to try all combinations, but 16^32 is a huge number, and there are probably only 30-50 images.
For the game images, the number is a 64 digit one, not a 32 digit, so the possible combinations are 16^64. While there would be more images to grab that way, the images are the same ones that are used in the catalogue, so Arx Fatalis would have an image, even though it's not part of the sale. For more info, I can refer you to the summer sale, when on day 3 we did have most of the deals figured out.

It would be a long list, everything except what's on CarrionCrow's list. ;)

Think it'd be useful for people to have the entire discount listing in one shot?

As you already did, I think it's easier to list what ISN'T discounted.

Another one to add to the list of discounted games - Unrest SE 50% off.

You'll get a list of about 10 Titles when you go to checkout - I saw these @ 50% off for now :

Banished
Dreamfall: Longest Journey
Democracy 3
Wizardry 6 + 7
Night of the Rabbit
Still Life
Shadow Man
Outlast
Avadon 2: The Corruption
Redneck Rampage Collection