Are you into real time strategy games? If so (and if you haven't already played these games/ own them already), I recommend anything developed by Paradox, specifically Europa Universalis 4 (renaissance Europe) or Hearts of Iron 4 (World War 2). They're extremely fun games, however they are pretty difficult with a very steep learning curve, and they are a bit expensive ($40 a piece I think), but all and all those two games have been some of my most played games on Steam in the last year or so, and they are relatively realistic.