Rockaberry's is a well-established hang out spot in the West Island (You do have some downtown, but I never go).
It started with the one on Sources (in D.D.O.) and now I mostly go to the one on St-Charles (between the 40 and 20). Both have outdoor terraces, but the one on St-Charles is bigger and more enjoyable in my opinion.
They have great sangria (white and red) to enjoy, are known for their desserts: amazing pies that you can't find anywhere else in Montreal. Apple crumble pie, Apple crumble cheesecake (one of their newest), Raspberry crumble pie, Truffle, Toblerone cheesecake, Orea cheesecake, you name it, you can find your fix here. They also have excellent nachos to share (and the appetizer one is great and more than enough for 2). Their clubs are also awesome.
A lot of people study there too! It's '''the more upscale study place of the West'''' haha. Good times, food and hockey game in the background. The fun thing about the one on Sources, they have a fireplace. Studying is good but it can get super loud (like nightclub) around 8. Not too pleasant. Even if just to go without studying, hard to hear each other speak.
But all around a fun place worth going to!