Answers:
Grain alcohol. 190 proof. (95% alcohol)
If it were any stronger than 95% it would evaporate. So to be precise as strong as it gets. I'm an ex-bartender. Always listen to your bartender. my answer is correct. All others are wrong.
Other Answers:
natty alcohol
any very strong rum (something approaching Navy Rum) or Absynthe. Don't know how you spell it but it's disgusting...
Starbucks.
Moon Shine
From memory a while wager on, the Guiness Book of Records listed an Ouzo as the uppermost. This may now enjoy changed.
Everclear...it is a particle alcohol, but it will burn your mouth if you out it in near. And it will really hurt if you try to swallow it. It must be mixed with a non-alcoholic beverage.
If you can't find that, Bacaradi 151 is much more adjectives.
everclear
Everclear, so strong its unjust in some states to put on the market..