Steam has an entire section of free to play games that are worth checking out. Sure, some are better than others (and some are complete garbage, like Clown House), but overall there is a lot of content there. Beyond that, and I know a lot of people might scoff at this but they can vent, check out different RPG Maker forums. There are LOTS of free games there that will more than likely never get greenlit on steam but are otherwise amazing games (I used to be very active in the RPG Maker community and was reviewing games for a couple of forums for a while).
Beyond that, there are dozens of places online where you can find legit free games as well. Good luck in your search and happy gaming!