Dont know what kind of games you are in to but hear is a small list of some games from different classes
Cities Skylines, Company of Heroes 1 & 2, Sins of a solar Empire Rebellions, Homeworld 2 RM, and Kerbal Space Program
I have used this site for some of my steam games... They have a great CS and a good refund if you pay the $1 or 2 so if you get a bad code they will give you your money back... Many of the youtube channles I watch have links to this and give 3-10% off... They also have Battlenet, Orgins, and others. When I have a few bucks I go and see what they have most of the time I pay less then $10 for games that if I bought them from steam or others it would be 2x as much or more.