Trick will be finding one you can actually hear each other in.

Anyway, the Pet Shop is actually not bad for casual drinks.

Iron Monkey has a bunch of different little places you can kind of tuck yourself away in.

Archers is far from a dive, but has a nice small bar and good cocktails.

O' Haras is a classic standard pub. Ed and Mary's is probably as friendly a place as you could possibly find, and you'll likely have 4 other interesting characters to talk with/listen to while there. I just talked myself into Ed and Mary's. Go there.