User Experience Week is an intensive learning experience put on by the ultimate usability gurus from the Neilsen Norman Group - Jakob Neilsen, Bruce "Tog" Tognazzini and Don Norman. And you haven't learned ANYTHING about development until you take a class from the "Tog".
But for my money, the real brains of the outfit is Hoa Loranger (Thank Pete she's available for hire in addition to these conferences, I know I would have been lost without her many a time). If you're new to the business or need a refresher, take Hoa's "Rapid Iterative Design" course on paper prototyping. It really changed my entire outlook on development and testing when I took this course many years ago - and continues to help me today.
Okay, since I'm not making commission or anything, I'll stop gushing now. :)