Jay's Saloon is a tucked away local secret that is off Clarendon's main strip at 10th and Hudson Street. Its a great little dive bar with a very friendly staff and low priced offerings. I usually go for the crab cake sandwich, which is decent.
I was able to take advantage of their happy hour beer specials today, which last from to 4 to 7pm weekdays.
$2.50 domestic bottles
$2 mugs
$7 for a full pitcher
$2.50 for house wines
It doesn't look like they offer the $1 domestics anymore =(
Check out Arlington Happy Hours for more after work specials!
Also, the Cookography blog has a great article listing the best restaurants in the DC area.
