The Mason Lounge is a cozy bar with a fantastic tap. It retains neighborhood watering hole cachet while simultaneously catering to a "hipster" crowd.
Every time I've visited, the tap list delights. Amazing beers at very reasonable prices.
I like that there are a variety of seating alcoves. I've always been able to find a place to sit, and you can hear your friends over other patrons without straining or yelling (some bars escalate to a cacophonous din as the hours grow later).
The bar staff has always been busy, but very friendly.