We're into our second week of our current crunch push, and while it is a bit disruptive to one's usual schedule it is just immensely satisfying to see how much stuff is going into the game and the level of polish that it reaches.  During crunch we meet every evening after dinner to go over the latest build and share comments, etc.  There was a very tangible moment for me watching tonight's build where I just couldn't stop thinking "wow, I can't wait to be sitting down and really playing this game".  Very exciting.  We'll be tying it off soon though -- we really try to limit our crunch bursts to no more than two weeks if possible, beyond that you really start to lose the boost in productivity.