At the top of the Rambla is a cafe-bar that, like so many, has undergone several changes of owner/ name, but for the last few years at least, has been called Can Turky's.
It's location makes it a great place to sit and enjoy a coffee, whilst watching the world go by. I also like it because sometimes it is slightly quieter than the cafe-bars that are more central. The waiters are all friendly and are prone to throwing out the occasional word of English too.
They have a full range of other drinks and a fairly extensive snack and meal menu. I can particularly recommend their bocattas (small baguette type sandwiches).
Next time you're in VnG why not give them a try?