They serve only one beer at U Fleků (Křemencova 11, Praha 1), but it was the best beer I tasted on my tour through the Czech Republic, Slovakia, and Hungary. Second to that was the beer at Pivovar Novoměstský (Vodičkova 20, Praha 1), which had better food. However, the beauty of U Fleků is that they keep bringing you fresh mugs of beer and ice-cold shots of Becherovka all night, so the food, while tasty, is not the main focus of your time there. Bring friends with you, or make new ones. Regardless, you will have a good time.