Big publisher sales are always a great way of filling any big gaps in your Steam library, especially if there's some franchise bundles. Deep Silver is having a weekend sale on lots of PC titles, including bundle deals for Dead Island and Saints Row: The Third, which are $16.99/£13.59 and $14.99/£12.49, respectively.
There's some great titles from 2013 that are also cut in price by 33 percent including Saints Row IV ($33.49/£26.79) and Metro: Last Light ($26.79) and errr.... Ride to Hell: Retribution which is cut down by 75 percent to just $4.99/£4.99. If that's your thing.
There's daily deals happening within the every 24 hours, so check back to see if you can save a few more bucks on other titles like the Secret Files series, Risen, Sacred, and Nail'd. There's a couple of things I'd like to check out and really, I should have got Saints Row IV by now.