Games With Gold has an awesome lineup for August, including Bayonetta, featuring the spectacled, raven-haired, pistol-wielding librarian. The game also joined Microsoft's growing list of backward compatible titles for Xbox One.
Bayonetta will be free for Games With Gold members from August 1-15. Red Faction: Armageddon, which also is now backward compatible on Xbox One, will finish out the month as the freebie from August 16-31.
As for the games created for Xbox One, Slime Rancher kicks things off and is free the whole month from August 1-31. Trails Fusion fulfills the weird cross-month title, being free from August 16 to September 15. All four titles will save you almost $90.
You still have time to grab a few of July's free games. Runbow, Kane & Lynch 2 and Lego Pirates of the Caribbean can still be had if you are desperate to fill out your library.