Butternut's Moo Thunder Stout. It had a nice thick head, warm roasted coffee and malt aromas, and the finish had hints of chocolate. Best part? It comes in a simple 120z can!!! Classic.
Ashtray Heart by Evil Twin.
In addition, I highly recommend the barrel-aged Black Hole series by Mikkeller. Aging in various sorts of barrels adds some interesting flavors to this delicious Imperial Stout!