Fun fact: Smirnoff Vodka has 16 flavors with the newest one being Pear!
A typeface designer named Jesse Ragan designed the typeface for Smirnoff. The closest font to it would be Bell Centennial Std. The letters look like they are curved on the baseline but they are actually straight. To me the letters are very simple, I like how they have a shadow. I wouldn't change the font to another I think it fits well with the bottle.
Like the font, dislike the font?
Sources: http://en.wikipedia.org/wiki/Smirnoff_vodka
http://en.wikipedia.org/wiki/Jesse_Ragan
http://www.jesseragan.com/work-smirnoff.html