In 1916, Prohibition made many Halifax bootleggers and rumrunners rich, though the Temperance movement also forced Haligonian drinkers underground in their search for alcohol. The fact that for two hundred years and two World Wars--and the times since--the world's navies treated Halifax as a major port city didn't hurt either. Today, Halifax has an active after-dark culture, with one of the highest numbers of bars and nightclubs per capita in the country. On the weekends the dance bars pack early, and the most popular ones keep the party going until 3:30 a.m., which makes the city pretty well world class.
There is a great degree of variance in how Haligonians measure their favourite bar. Live music, diverse clientele, a great DJ and a sizeable dance floor are one element. The hustle on the dance floor, and the "interestingness" of the other clientele, not to mention plenty of seating for a spot to get away and chat are also important.
For the party animal in you, always ask around, to see if there is anything just-opened. It is a common sight to see Haligonians club-hopping from place to place. They know where the fun is!!
Link to Halifax's Top 5 Bars lists.