GOG are running a superb one-day promotion that slashes the prices of a huge amount of quality software. The Mutator Sale allows you to pay an extra £1.29 to receive a random extra game for every three you pick, which could be anything on this list.
It's a fun gimmick, but the raw savings aren't messing around. Shadowrun Returns and the surprisingly excellent Aarklash: Legacy are £2.49 apiece. Trine 2 Complete, Driftmoon, Project Eden, classic Divinity games and Dust: An Elysian Tail are all under £2!
Well worth a look for thrifty PC gamers and retro fans alike. Thanks to jaystan @ HUKD!