Humble Indie Bundle, with all four PC games currently on offer at ridicucheap prices. Pay up $1 and you'll pick up Darksiders and RF: Armageddon, with the soundtracks to both included along with the 'Path to War' DLC for Armageddon.
However, if you're willing to pony up more than the average paying price, you'll also get Darksiders 2 (plus soundtrack) and RF: Guerrilla. At the time of writing, the pair can be yours for around the very, very silly $7.50 mark.
Meanwhile on Android, there's another Humble Bundle for the platform called the Mobile Bundle. Featuring in the latest charitable collection are Contre Jour, Anomaly Korea, Plants vs. Zombies, and Bladeslinger. As ever you can pay what you want, but an average-cough up (around $5.50 at the mo) lets you unlock the secrets of The Room, and generally shoot up stuff in Metal Slug 3. The soundtracks to all, except Contre Jour, are also included.