I never have! Ever! And it's weird because I've broken a number of cell phones in the past by chucking them against a wall or the ground—there was a time when I was a thrower. But I've never thrown a drink, never in someone's face. I'm kind of sad about it.
I think I would like to throw a drink in someone's face. I bet it would feel invigorating! Alas, in my old age, I rarely get angry enough to do something so dramatic. And Paul Constant made the good point that throwing a drink on someone in 2012 is much different than it was 20 years ago because these days so many people have hundreds of dollars worth of devices on their person. Imagine throwing a drink on someone who deserved it, making a scene and feeling like a bad ass, only to get a $300 bill because you ruined their precious cell phone. That'd certainly take the wind out of your sails.
Not only have I never thrown a drink on someone, but I've never had a drink thrown on me nor have I ever witnessed a human throw a drink on another human (out of anger).
Tell me your drink throwing stories! I want to live vicariously.