The variations on this theme are perhaps infinite, given the variety of both the types of ice cream and styles of beer. In Fred's version, it's usually a stout (if memory serves). One might successfully pair chocolate, coffee, or vanilla ice cream with stouts, but if you're going for a high-alpha stout, you want to avoid vanilla. In my recent experimentation, a rule of thumb is that sweeter beers tend to work better than hoppy ones (I found great success with Black Butte Porter). Hops have a very different type of bitterness than coffee or chocolate, and it clashes with ice cream.
This summer I may experiment with lambics and fruit ice cream, or perhaps a dubbel. Your mileage may vary, but regard all efforts as worthy scientific investigations. You may discover something surprising. Oh, and one other important bit of advice. Don't put the ice cream in first. Beer reacts with sugar and you get a glass full of foam.