Continuing the naughty yet entertaining off-topic discussion..
I love Arma 3, but I really dislike the Vanilla setting and therefore campaign etc. The very best experiences in Arma 3 come from playing it online with a group of folk who play it tactically. The game is so powerful (similar to CM in terms of their seriousness) that small-unit tactics work in their engine. Fireteam bounding keeps you alive whereas blind charges will fill you with holes.
I have quite a few videos of playing the Arma series with a group called United Operations, they are an open community that tries to promote realism. This video is where I am leading a severely under strength platoon in an ill fated assault on an enemy fortified position https://www.youtube.com/watch?v=QoHQ5yleOaU Everyone on my side is a player, against computer controlled enemies. There were about 15-20 of us if I remember correctly. The server currently peaks at about 70 players on a friday.
I apologize in advance for my lack of knowledge and skill.