Numero Uno Coffee. 83 Regent St, Chippendale. A little off the beaten track, but likely to see some good foot traffic as the local cafe when Sydney Central apartments come online. This is one of those places that cares deeply about coffee: they have naked portafilters, and a very narrow range of menu items - mostly sweet things, but with a few sandwiches thrown in for good measure.
Coffee is really good - I haven't had great experiences with Numero Uno before, but whether they've lifted their game, or it's just the extra attention to detail given here, it's worth a look. No decaf, though: they're not prepared to offer it, as they can't move enough volume to keep the beans fresh.