IPAs have caught my attention as of late, although I don't drink them very much now.
Sweetwater 420 out of Atlanta, GA
Sierra Nevada Pale Ale
Magic Hat #9
My favorite if it wasn't so fattening would be Newcastle Brown Ale. Yes, I've had better and had worse but the extreme micro-brew types aren't always available and consequently they're just a novelty.
Possibly my favorite overall that I can no longer find (since I haven't been to Asheville, NC in a while) is from the Catawba Brewing Company out of NC, and called Indian Head Red Ale. Can't get it anywhere around here any more.
It was only draft when I was able to get it. That would be an example of an extremely rare micro-brew that's good but not available all the time.