Public House, best known as the home of SF's most impressive collection of flat screen TVs (27 in total) and craft beer, hosts Cask Ale Nights every Thursday. All cask ales are $3 for the night.
Be sure to try the Billy Sunday Bitter cask ale, which is brewed by Magnolia Brewery exclusively for Public House. It's a pale copper-colored, English-style bitter built around the heirloom malt variety, Maris Otter. It's moderately hopped (24 "bitterness units"), with two English-originated varieties: Goldings and Challenger.