I've got to jump on the bandwagon for this one. There are plenty of good habits.
For example, you can make it a habit of not having bad habits.
You can be a habitual giver, helper, and/or lover.
Conversly, bad habits can range from drug abuse to people abuse.
It's all very relative. After all, some people consider farting a bad habit, while others see it as part of a natural digestive cycle. Societal norms shape habits, placing them in the realm of "good" or "bad."
For my part, I habitually go on HubPages.com... though it'll be harder with college starting.