Rainbow Six Vegas and Splinter Cell Blacklist and Chaos Theory were awesome for this - especially for 2 people.

If you have 4 then SWAT 4, Ready Or Not, Operation Flashpoint: Dragon Rising, ARMA 3.

Hard disagree, it lets me achieve more and avoid procrastination. It can help you not get caught up on small errors, and be like a junior colleague given you complete attention when you ask for different proposals, etc.