One great pub has already been mentioned, check the Patrick’s Pub review. I like Sir William’s much more. I may drink literally anything I want, because I can choose from more than 120 different beers from Ireland, England, Germany, Belgium, Slovenia and other countries. Not to mention 30 different wine and whiskey brands. For me it is also a more peaceful environment, to think and talk with my friends.
Their specialty is the monthly organized beer tasting. It is an extraordinary occasion occurring every last Monday in which I once participated. I paid € 16 and tasted 6 different beers, listened to the explanation about the origin, brewing process and taste, just like a real enologist. I recommend you asking the barmen for their recommendation, because they never let you down.