One of the "white whales" of the beer world is a beer called Pliny the Younger, from Russian River Brewing CO. in California. This brew is released once a year, not bottled, and can only be found in select places. Denver has seen it in a couple of beer bars in the past, and this year seems no different. It's arriving in Colorado today and should be tapped later this week.
So, what is it? Well, RR also brews a beer called Pliny the Elder that is widely enjoyed and released sporadically--for lack of a better term. It's a double/Imperial American IPA, which means it's loaded with American hops, and that means it's flavors are more focused on citrus and tropical fruits. And it has a bite, a nice, lovely dry bite to it. Pliny the Elder currently ranks as #2 on BeerAdvocate's top 100. Pliny the Younger is #3 on the same list w/ about a 1/4 of the number of reviews. While the Elder is a double IPA, the Younger is billed as a triple IPA. More hops, more bite, more alcohol due to more malt, as well. It's quite good.
Falling Rock Tap House is the only place I know for sure will tap it. Last year I saw it at Vine Street Pub, too, but no word from them yet this year.