At face value, state-level minimum wages range from as low as $5.25 to $9.47, but the actual purchasing power of those wages is all over the map.
Adjusted for prices by state (using an average of regional price parity calculations from the U.S. Bureau of Economic Analysis, for 2008-2012), the chart below shows where the state minimum wage has the most purchasing power and how that differs from the face value of that wage, calculated for a 40-hour workweek, before taxes.
(Use the bottom axis to sort states by the dollar value of minimum wages in effect Feb. 2015.)