Oh lord, it's really happening. The Christmas sales are here. First out of the gate is GOG.com (opens in new tab) , purveyors of classic PC games and newer indie releases. And The Witcher 2, which doesn't quite fit either category.
For the next 22(-ish) hours, they're offering 75% off their Bullfrog Favourites collection (opens in new tab) . For $11.92, you get three Populouses, two Dungeon Keepers, Theme Hospital, Syndicate and Magic Carpet. While you have to get all the games to qualify for the full 75% off, any you already own will helpfully count to the total, with the price adjusting accordingly.
Also! For the next two days the site is giving away (opens in new tab) Duke Nukem 3D for free. Now you can use the cheeky 16 year old FPS to wash away the bad taste of any sequels that may or may not have happened.
Also! The whole site is holding a 50% sale off the majority of its catalogue until January 3rd. Looking through, it seems to include just about everything that isn't called Baldur's Gate. It does , however, include the other Infinity Engine RPGs, with both Icewind Dales and Planescape: Torment now costing $4.99. You can also pick up The Witcher 2 at a 60% discount of $11.99 (just under £7.50 in real money).
You can browse the full list of discounted games in their catalogue (opens in new tab) . There's some brilliant stuff in there. There's also Myst.