Seems we have several polls asking this question. Most recently THE DAILY MEAL is asking this question.
What is nice about this survey is you can vote for as many as you think are deserving, so you don't have to just vote for one. The other part I like is it separated in regions. The choices for this poll are quite good, but the Southwest is woefully underrepresented. The Midwest, West/Southwest, and Northeast are really the big names in craft brewing. VOTE FOR YOUR FAVORITES HERE!