I go for Normal mode because that's prettymuch always the way the games were intended to be played. On the rare occasion that Normal is too hard for me, I don't have any problem dropping down to Easy. Hypothetically, if Normal were too easy, I'd just as readily go up to Hard, but I can't think of any games I've played that have had difficulty settings where Normal was too easy. I'll usually only go through the harder modes if there's something to be unlocked by doing so; I don't think I've ever done it for fun.