I like big houses because, if the house is big enough, you forget what it looks like and each time you go around it seems like a whole new house.
However I would have to say I like small houses better, for the same reasons that CPhill and EP already said.
But is a small house really easier to defend? If you hide inside the middle room of a big house, attackers have to get past more walls to get to you than they would if you were hiding inside the middle room of a small house. A big house has more defenses already in place than a small house.
But the real important thing is land. You need to have land in case of a zombie apocolypse, so you can grow your own fruits and vegetables.
