Modern graphics and an open world MMO that doesn't interfere with its aspects as a first person shooter. Find a good outfit or just play with a Squad / Platoon, either way you're guaranteed hours.

A game you can still sit down and play as a group, albeit it is far more competitively minded usually as playing against the AI as players would be rather one-sided at the end of the day.

A great game to join into as a Regiment or Clan, especially with the Napoleonic Wars DLC and the many mods that you can download, from the Roman Era to Star Wars or even World War I.