Sunday River Brewing Co. They have a pretty tasty alt and porter as well, but the flagship is the standout. (A few snowflakes are falling lazily down--whether it's evident in this photo remains to be seen.)
A couple days ago, Sally and I drove through Portsmouth, NH--where there is a fantastic brewery and possibly the best oatmeal stout I ever tasted (key: 30% oats in the grist). On nitro, the head was thick enough you could float a brick on it.
I'll write more--but all in good time. Now I have a football game and this IPA to attend to.
Update. The snowflakes are no longer lazy.