Carbs! I love pasta prior to any endurance-related activity. Then again, I just love pasta.
The rule of thumb I've been taught is that sugar is for the short run, carbs are for the long haul, and protein is essential for recovery.
Sugar breaks down fast, and so is good for immediate energy. The downside is that sugar dehydrates you, and you'll run through your energy supply quickly.
Carbohydrates are complex, and therefore take longer to break down, but hold more energy overall, making them the most essential for long-term energy. Protein is a must for muscular recovery. Without it, you're going to do nothing but damage to your muscles. Hope that helps some.