Gorilla would win. Agility + freaky crazy strength =p Read animorphs, lawl or zoobooks. A gorilla weighs like 900 pounds? Over 400 at the very least and thats all muslce I think. Bear has more way more mass but less muscle im sure and I don't think it'd move as fast. Meh, I know I know some reasons why the gorilla should win, my memory is just off =\. Go go edit button then.
id say the bear is stronger, but the gorilla would be smarter..depends. but prob a bear. claws are a BIG advantage.