Scottish brewer Brewdog is responsible for one of the worst beers I've ever tasted (one they seem to no longer make, which is good because it tasted like the ashes left over after a campfire), but in the era of "extreme" brewing, they've certainly upped the ante as far as alcohol content goes. Move over, Dogfish Head and your hop-heavy IPA's, Sink the Bismarck takes alcohol levels to a new height, reaching 41% by volume. By comparison, Jack Daniel's is 80 proof, or 40% alcohol by volume.
I'm going to guess Sink the Bismarck probably doesn't taste great, and you're supposed to sip it like hard liquor, so it's barely even beer, but I think I'm willing to take one for the team and our loyal readership and track down a bottle to try for myself, although it might take some negotiating around my house to convince my wife that a $65 bottle of beer is a "business expense".
Updates to come.