Most recently...Sierra Nevada 30th Anniversary - Ken & Jack's black barleywine
Extremely limited at this point and if you find it pick it up. I love barleywines so the idea of a black barleywine was pretty cool. Was able to pop open a bottle a little while ago and I absolutely loved it. This is a beer you can cellar (age) for awhile and it'll taste that much better.
Sierra Nevada 30th Anniversary - Brewers Reserve Grand Cru
Last of the series of the Anniversary series. Once this is gone its gone. It's a mix of Sierra's 3 staple beers. The Bigfoot, Pale Ale, and Celebration. Awesome beers alone, but this blend is fuckin' excellent. I would definitely pick up a few bottles while you still can. Nice hoppiness without being in your face. I hear you can age this too, but I don't know for how long since it'll start losing a lot of that hoppy bitterness as time goes by.
Stone Brewery Vertical Epic 10/10/10
Stone does this beer every year and every year it's different. This time around they made a Tripel and mixed in a bunch of shit which includes white grapes that are normally used for sauvignon blanc wine. This is one belgian that makes really good use of the fruit flavor. It's not one of those beers where you have trouble identifying the flavors. You can definitely taste the grapes and it works well. Limited and once its gone its gone. This would definitely age well if you wanted to cellar one or two, but you really wanna enjoy a bottle now too.