The only thing better than beer is free beer, and on occasional Thursdays — usually once or twice a month — the Rock Bottom in downtown Denver gives away free pints from 6 to 6:30 p.m. to introduce its newest beer on tap. And brewmaster John McClure is always working on a new brew, whether it's a seasonal specialty, a twist on a classic or something completely different. The Colorado-founded Rock Bottom chain was rolled up into a much larger corporate entity last year, but maybe the suits won't notice these priceless free-pint nights. Next up: Snake Spit India black ale, which will be tapped on April 14.