Moscow Mule

I wouldn't say it's the "best" by any stretch of the imagination but it's pretty solid for what it costs.  

I go up to Mount Stowe in northern Vermont once a year or so and I always stop by Smuggler's Notch Distillery when I'm up there.  They make my favorite vodka.  I'm more of a whiskey guy who is just venturing into the world of tequila, but this vodka is terrific.  It's smooth and is perfect on the rocks with just a splash of a fresh lime squeeze.