I am a big fan of the black lab bar. Â Particularly the owner Matt and his big arms (they are seriously very large).
There are only two negative things that I can say: Â (A) I think they could rearrange the couches so that they are more efficiently used (consider building stadium seating or lofts), and (B) the young lady who frequents the bar drops a lot of s-bombs.
Other things to consider - MIKE KAGEY frequents the bar. Â Mike frickin' Kagey. Â If you get a chance, just give this guy a big hug.
All in all, I rank it as the best bar in Concord Massachusetts. Â Not sure it can hang with Carlisle, but definately top notch for hootsy-tootsy Concord.