Most expensive drink I've seen to date is Chateau Mouton Rothschild 1945. It's now about £12,000 per bottle, and is probably the most expensive drinkable wine available.
There are more expensive wine bottles in circulation, but none of them are, as far as I can tell, drinkable any more, because they're over 200 years old. And no one is going to open the bottle to find out. One of these was a bottle of Chateau Lafite that originally resided in Thomas Jefferson's wine cellar, and dates to 1787. It was bought as a piece of Jefferson memorabilia for a whopping $156,000 in the USA, but I suspect the contents have long since ceased to be potable. A Chateau d'Yquem from his cellar fetched a mere $100,000 (white wines are valued less than reds, regardless of vintage, apparently).
Another bottle from his cellar, a Chateau Margaux, was knocked over by a waiter and broken. Insurers paid out a frankly amazing $225,000 for that incident.
A 1907 Heidsieck champagne from a shipwreck fetched $275,000 at auction. It was originally destined for Tsar Nicholas II, but the ship carrying it was torpedoed before it could reach port. Amazingly, the bottles were salvaged intact from the shipwreck. I don't think anyone is going to test if it's drinkable any time soon, even though it may technically be so.
