How recent are we talking about and what did you play recently? What sort of games would you like to play, any preference there? Are AAA games okay or only indie games maybe? There are many question open, so its hard for anyone to recommend something for you. Right now Steam has a sales event going on, where lot of games are cheaper or very cheap price.
Little tip, you can use the Steam search by showing Singleplayer games, Games only (no DLC), hide free to play games, show games with discounts only and hide ignored and those you have in your library already: Steam Search