For me its between Kessler's "Whiskey" or whatever it really is (I wonder if you could run an engine on it.....it tastes so vile you probably could!) or a bottle of extremely cheap "chianti" wine I bought at a hostel in Italy. that was some awful wine. Horrible purchase too, as we had just drank some wonderful delicious chiantis prior. It left the worst aftertaste let me tell you.

Ten High bourbon is also terrible. Honorable mention.