When we were living in Camden Town, we mostly frequented more rock-y places, so I can't advise specifically.
But if you come over to Kilburn (20 minutes from the Camden Road overground to Brondesbury), there are loads. The Sir Colin Campbell on the high road and McGlynn's on Willesden Lane spring to mind.
Although the latter is something of an old-Irish-man pub, the first time we were in there, tabletop jigging and a lock-in went down. (Don't ask about that night, I only remember about a third of it.)
Never been to the former, so I can't vouch, but most of the pubs here are proper Irish, and the Irish will make sure you know just how Irish. Because Irish! (Love them, but man, my liver can't do take a night with the Irish too often.)