On the back wall they had the 'Holy Grail' of spiciness - Blair's 16 Million Reserve:
That's it. The race is over. It's chemically impossible to get any hotter ! Not really a sauce, but worthy of inclusion.What you will find inside the Famous Reserve bottle is amazing, a 1ml pharmaceutical grade vial filled with this Pure Capsaicin Crystal.
Check out The Hot Sauce Blog. The author was brave (crazy? stupid?) enough to add a grain to a bowl of tomato soup, and subsequently made the mistake of giving it to his wife. Read the blog and the comments, and you'll see the testimonies of a few "I can take anything" idiots who've actually tried it straight.
Chile-head that I am, I had my wife take a photo of it, just to say that I saw it. At $275 it was a little over my budget. It's not really something you would use -- more like a collector's item.
I ended up buying another hot sauce -- Blair's MegaDeath -- for my collection -- alleged 550,000 Scoville Units (see link for explanation). They made me sign a disclaimer before purchasing, explaining that after a certain limit they require the disclaimer for legal reasons, citing possible customer misuse of a life-endangering product. (As one commentator noted, after 700,000 SU's you're not really dealing with "sauce" but rather an extract, not intended for direct application).
Here is a list of the hottest sauces known to man.