"Best brewpub" depends what you're looking for. I really like the Breckenridge Brewery for flavor, eye candy and variety, but you do have to go to Breck to visit. Likewise, the Dam Brewery has some good beers and a decent menu, but it's in Silverthorne. I wish New Belgium had a pub attached, but there are plenty of local pubs that serve it instead. Coopersmith's in Ft Collins has a great combo of menu, beer, and eye candy as well.
Local to Denver? Unfortunately I can't think of anything that really rocks. CB+Potts is decent, although I've found their beer selection slightly lacking at times.
Jim - 96 Cherokee