For MTB, my choice, brand-wise would be:

1. Kona
2. Specialized
3. Trek
4. Everyone else

Others may disagree with my choices. I've owned a Kona Dew Deluxe (GREAT hybrid!) and currently own an '06 Specialized Rockhopper. I have nothing but good things to say about either Kona or Specialized.

I believe that if you want to ride centuries, you'll be better served by a true road bike (even a used one) than a hybrid such as the Kona Dew. The Dew is a great bike, and an unbeatable value for the money, but having lighter wheels and drop bars are strongly-desired virtues in a century bike. Happy shopping!