Welcome once again to Shoestring Gaming, where we find all the sales across the Internet so you don't have to do the research yourself. Pick from a selection of games currently on sale or take a look at some popular free-to-play games if you have to pay for other less important things like rent. Remember, most of these deals are only for a short amount of time so jump on them while you can. Except the free games, those will probably be around for a while, and still be free.
The theme this week seems to focus around The Witcher 3: Wild Hunt, since this incredibly popular title is on sale pretty much everywhere. You can get it for 53% off (or $27.99 USD) at Green Man Gaming. At GOG, you don't get as big a discount, but you can get the entire Witcher collection for 49% off. Can't play on your PC? Well if you own an Xbox One and have an Xbox Live account, you can also get The Witcher 3 for 30% off from the Xbox Store (sorry Playstation owners). The Witcher 3 is also $29.99 at the TechRaptor GameFanShop. Also on sale pretty much everywhere is the new release STASIS, which you can get for 20% off at Green Man Gaming, GOG, and Steam.
Be sure to check out the TechRaptor GameFanShop as well, where there are plenty of good deals that will support TechRaptor at the same time. As mentioned above there is The Witcher 3 for $29.99, but also Call of Duty: Advanced Warfare for $20.99, Alien: Isolation for $17.99, Battlefield 4 for $10.67, and many more!
Steam always has a lot of great deals. This weekend only you can save up to 80% on Focus Home Interactive games, including Farming Simulator 15, Styx: Master of Shadows, and Game of Thrones. If you don't see anything you like there, there's always lots of other Steam sales. This weekend all Steam users can try out Evolve for free until Sunday afternoon and purchase for half off. You can also enjoy some Deus Ex for up to 80% off. If you're looking for indie titles, right now you can get the retro platformer Out There Somewhere for 96% off (that is, about twenty cents). You can also get this game as part of a the Developers Alliance Bundle along with three other indie titles, Polarity, BEEP, and Camera Obscura for $1.49 USD.
At Green Man Gaming you can save 23% off all purchases not already on sale using this code: SAVE23-WITHGM-GSEP15. That voucher is good until 5PM UTC, but always keep an eye on the front page of the site for new vouchers (pro-tip: this voucher works for ALL games, including Mad Max and Metal Gear Solid V—just sayin'). Most of their deals are listed above, but as always if you're a member, you can enjoy the deals on the VIP 
page for several AAA titles. At GOG save 10% on your preorder of Soma, 20% on Satellite Reign, and 50% on The Settlers: Rise of an Empire.
At GamesRepublic their perpetual Monster Sale still includes Tomb Raider and Lara Croft titles for up to 75% off. Also right now you can use the code GRNEW-GAMES-20%OFF in order to get a copy of Mad Max and Act of Aggression for 20% off, plus a free copy of This War of Mine (which you can also get with any purchase of a recently released game).
On Xbox if you have Xbox Gold you can take advantage of their Activision Sale, including Prototype and the Call of Duty series. Xbox Gold players can also get Assassin's Creed and Rayman titles for a discount. Not much in the Playstation Store, but you can get The Last of Us for Playstation consoles for up to 50% off on Amazon.
Broke? Here's some recommended free games from GameJolt. Going Nowhere came out this week, a pixelated exploration game that is just as trippy as you'd expect most free indie games to be. If you want something a bit sillier you can try the retro platformer Duke Dashington. On Kongregate, you can try Cube Escape: Case 23 if you enjoy point-and-click horror games and fairly self explanatory titles. Or if you want something more complex, you can try Star Runner: Genesis, a full on sci-fi adventure game.
As always if there's any deals we missed, please share them with your fellow man in the comments below, and enjoy yourself.