I visited Bratislava a few weeks back, as I visited a few European cities this summer,. Bratislava was by far the worst I visited. From the cities I visited this summer I would personally recommend Budapest or Berlin for a stag, probably lean towards Budapest.
Can I ask what was so bad about it?
It seemed that everybody was out to rip you off which somebody else said earlier. Small things from overcharging in the taxi by almost triple compared to the same trip the day before, rounds completely different price depending on who served you in the bar. Obviously only small things, but whole place wasn't really for me. The main square wasn't bad, but not as good as others I have been too.