Cafe Europa is a classic.
You can get very decent food until 4 AM which is unfortunately still pretty rare in this city.
The cocktails are pretty good - you won't have to break out in tears when you taste their Mojito.
While I definitely wouldn't go there for the coffee alone, you can drink it though and be OK satisfied.
The staff varies but mostly they've been pretty cool and amicable.
Cafe Europa is regularly overcrowded before 1 AM.
You can get vegan food there but there's not a lot of choice - salad or the seitan sandwich with mustard instead of the curry sauce. But at four in the morning that's more than often the thing that just hits the spot.