One of my favorite pubs in Montreal, close to the centre of downtown and right next to Concordia, there is always a good crowd. If you are looking for a good pint or a decent plate of pub grub this is my first choice. Most nights there is live music on the main floor, and a good cozy atmosphere, although it can get quite loud with a full bar and a band playing. Not my first choice if I need to have serious conversation.
A nice feature is that there are 3 floors, the main floor being the main pub, upstairs is more of a dance bar, and downstairs a quieter smaller pub.
Definitely check it out, well worth your time.