Great sandwiches, reasonable prices, good service, cool decor, interesting cocktails, and authentic Cuban cuisine.
If I weren't somewhat indifferent to Cuban cuisine, Cubana would get 5 stars.
I might be back regularly for the amazing coffee and (seen but not yet tried) deserts, but otherwise only the hardy cubano sandwich would bring me back again - although we tried the cod croquetas (ok, a bit potatoey), the habanero-glazed squid (more sweet than spice), and a side of slaw (dead bland - truly Cuban).
edited to add: Remember to ask for their mango hot sauce - it makes the place worth a visit all by itself. They should bottle it for sale at the counter.