To mention but a few in the heart of town ......... Cholos. Fidos. Holiday Hotel. Canibals. Pier Lounge. BC's. Blue Water. Ramon's. One of the best daytime hangs for ice-cold beer (also huge breakfasts starting at 6 am) and the best collection of recorded music in Belize - Estelle's Dine by the Sea. San Pedro can be one long pub-crawl.
Don't forget to catch a sunset with Barefoot Skinny at his Hammock House. It rocks!! And you get to go across the hand ferry!!! Great experience. But for the coldest beer on the island, nothing compares to Cholo's Bar.