Echoing Becky's experience, I too have found myself sharing popcorn with total strangers after having a few adult beverages, but c'est la vie - it's all good!
The Gin Mill is a fun bar with lots of friendly staff. I've seen some pretty good local musicians play here and definitely have played my share of shuffleboard and foosball. They used to do trivia here during the week - can't remember which night though.
The cool little deck gets really crowded on game-days and sometimes on weekends as well. It can be tough to get a drink up there, but no matter, just grab one from the friendly bartenders downstairs before you head up.
If you are looking for a cool little unpretentious watering-hole, you should give it a try.