Like any touristy cities,you'll pay more for drink in the main tourist area's,we drank in the old town square in the afternoon,which is probably a bit dearer than pubs 5-10 minutes walk away.
At night time you want to be heading over to Wencelas Square area for your adult entertainment,you got clubs like Darlings and Atlas that are very popular with stag weekends.You'll get a lot of hassle off the little Gypo, type street urchins,but if you like a bit of rough they'll do the business lol!
Watch out for the taxi drivers,they are fucking mental and nearly killed us a coupe of times.Do take a bit of time to look around though,it's a beautiful City and i'm glad i broke away from our party to have a look around the place.