It depends what it is, but I usually call the drink by its proper name. For example, if I'm going to retrieve a Coke from the fridge, I'll say something along the lines of "I'm going to get a Coke". If I intend to fetch a can of Dandelion and Burdock from the fridge, I'll say "I'm going to get a can of Dandelion and Burdock", and so on and so forth.

What's Dandelion and Burdock? Well, that's something for another thread.