State gasoline taxes
A federal sales tax of 18.4 cents is imposed on every gallon of gas sold in the US. Then, each state has the ability to tack on some extra state sales taxes on top of that.
this PDF chart shows that New York State imposes an additional 39.6 cent tax on each gallon of gas sold. (In January 2003, it was 33.55 cents/gallon.) The total amount of sales tax does depend on the county sales tax, as well.
So, New Yorkers pay a combined state & federal sales tax of 58 cents/gallon.
Although RI, CA, NV, HI, and WI all broke 30 cents/gallon for state sales tax on a gallon of gas, New York has the distinction of having the highest state sales tax of all 50 states.
Update: Fixed link.