Everclear. Potency/weight can't be beat, and you can use it as an antiseptic or as a stove fuel (or very fast-burning firestarter). I used to hike with a guy who carried his in a fold-up Platypus bottle. We'd roll into camp, he'd use it to fill his alcohol stove, light it, and then he'd casually take a swig from the fuel bottle while dinner cooked. The look on the other hikers' faces was priceless.

BTW, that's not begging the question. http://begthequestion.info/
I used to get it wrong all the time . . .