I'll admit to having a hard time opening "treasures," but I have so many now, I need to start. My bunker is officially beyond out of control. That said, there are only a couple that I just plain won't open for quite a while:

WT Tribute (though depending on how American Spirit is, I may change my mind)
Old Forester BIB 1966-1971 (the oldest whiskey in my collection)
Willett's #1 (I was fortunate enough to get a bottle, but I've never dropped $100 for a whiskey, so this would be tough to replace...impossible, technically, but what I'm getting at is what else would even come close?)

I think if I have a kid, I might open one of the above, and there's a milestone birthday or two that would likely be worthy of breaking one out, but short of that, I think these bottles are all good enough in and of themselves to be the occasion for which they are opened.