If you're looking to fill up your backlog on the cheap you might want to take a look at Humble Bundle's currently ongoing "Best of 2016" bundle. While it doesn't feature any games I've personally nominated as the "best of 2016", it does have a nice variety that should keep you busy for quite a while.
Most notably, it features the excellent Homeworld Remastered Collection, as well as Shadowrun: Hong Kong - Extended Edition which I found myself greatly enjoying. As for the full list of games and their pricing tiers, here's what the bundle has to offer:
Pay what you want:
• Else Heart.Break()
• Evoland 2
• Victor Vran
Pay more than the average of $4.01 to unlock:
• Rust (Early Access)
• Shadowrun: Hong Kong - Extended Edition
• Stronghold Crusader 2
Pay $10 or more to unlock:
• Homeworld Remastered Collection
If you're someone that enjoys strategy games, and doesn't mind them being slightly older, you might want to go for the $10 tier in order to grab the Homeworld Remastered Collection. The campaign alone is well worth the money given that its actually well written and interesting to follow, though I might be slightly biased given that Homeworld is one of the earliest games I remember. But if you're not a fan of RTS I would recommend just going with the $4 tier in order to grab a rather diverse set of games. Have fun!