My absolute favorite go-to on a Thursday or Saturday night is Brass Monkey in Adam's Morgan. A fun place to throw on a pair of skinnies and pumps when you feel like going casual for the night.
The bartender was cool owner was RUDE and I will NEVER step foot here again. My Yelp review: http://www.yelp.com/biz/brass-monkey-washington#hrid:LQomL68l1zkTlTRY9E7STA/src:self