Care for a glass of nice, cold Kool-Aid?

Today, I’m touching on the subject of cults. Instead of the Jonestown–David Koresh corner of this conversation, I’m more concerned with beer—that is, rare beer that people crave beyond all common sense. Three Floyds Dark Lord, the Bruery Black Tuesday, Russian River Pliny the Elder and Younger: Beer geeks would gladly give at least a piece of their pinkie for an unlimited supply of these limited-supply beers, which are often sold for exorbitant sums on eBay.

From the lambics of Cantillon to the Alchemist’s insanely hoppy Heady Topper, I’m in the process of compiling a list of the rare brews that cause drinkers to go gaga. And I need your help. Which beers do you see as being the rarest, most irrationally—or rationally, if the brew is really, really good—craved ales and lagers on the market?