The Microsoft 5-Game Arcade Pack includes Steam versions of Deadlight, Insanely Twisted Shadow Planet, Iron Brigade, Mark of the Ninja and Toy Soldiers, all for $10. The standard price for this bundle is $70, for a savings of $60. These games are also on sale individually on Amazon, Toy Soldiers for $2.50 and the rest for $3.75.
The Settlers Bundle offers Windows versions of Dawn of Discovery Gold, Heritage of Kings: The Settlers, The Settlers 7: Paths to a Kingdom Deluxe Gold Edition and its "The Two Kings" DLC pack, and The Settlers: Rise of an Empire Gold Edition. This bundle is currently $16, compared with the normal price of $85.
Also for PC, Fable: The Lost Chapters is $2.50, rather than $10. For Steam, the Age of Empires 3 Complete Collection is $10 via Amazon.