I prefer the Burger King toys cause they are bigger and better. For example I remember getting some really good Batman Beyond and Wild Thornberrys toys from them.
One time McDonald's gave away Olympic basketball cards of the Dream Team. They gave away packs of cards. It seems like you could buy the cards seperately or you could get them with a meal.
Today it seems like McDonalds is trying to shed their kiddy image so you don't see as many promotions like that. You see more attempts to appeal to the 20-somethings.