This is one of my recipes that was created on one of those "I feel like something different" days. I originally used Smirnoff's Black Cherry Vodka, which has notes of robust black cherry that are offset with the sweetness of grenadine and a bit of lemon for balance.
Smirnoff has since left the black cherry behind for simply 'Cherry Vodka' and that's a disappointment. However, there are a number of other great black cherry vodkas available and I would now recommend the Effen or Grey Goose options.
This is also great served on the rocks, in which case I also like to go tall and top it with ginger ale.