1. Philosophy in a good way: The process of seeking a better, happier lifestyle by giving deep thought into personal actions, habits and morals. Good philosophy is often understood to be to the benefit of society as well as to oneself. Religions often try to achieve this as well, at least on the surface.
2. Philosophy in a not-so-good way: The process of taking a set of personal beliefs and opinions and pressing them upon others without regard for the benefit of anyone other than oneself. Some would also say bad philosophy is the act of taking on a selfish lifestyle and making the excuse that this is the best way to live.
1. See Jesus, Buddha, etc. (Whether or not you're religious, they're both really nice guys.)
2. See Hitler, Stalin, Zedong, etc.
2a. A personal note to Ayn Rand: Rejecting altruism in philosophy is a little harsh. Try improving the life of someone who really does need it, then tell me that it's not going to make you feel any better.