Deciding on a bi-monthly(or monthly, depending on the game) game can easily be done thusly:

Have a nomination thread where members will each nominate one game. The first seven games are put into a poll, which is then voted on. We then play and discuss it. If the game is on Retro Achievements, we can hold races to see who gets the most points. Those of us who stream on Twitch or whatever can post their stream of the game there too.