A good friend is there when you need her. She says, "Why don't I take care of your kids so you can take a break for a while?" A not-so-good friend says, "I'd love to help you move, but I'm having my nails done that morning."
A good friend engages in an even give-and-take of thoughts, ideas, and feelings . The good friend says, "What's going on in your life?" and listens to your answer. A not-so-good friend cries, "Well that's my sob story - or at least as much as I can tell you in 45 minutes. I've got to go!" and never returns the favor.
A good friend has a life of his own and lets you have a life of your own. When you tell a not-so-good friend that you are going to do something with someone else, he says, "Oh. I guess I'm not invited" and doesn't speak to you for days.
A good friend is someone with whom you can do many activities - go to a movie, go bowling, hike or walk. A not-so-good friend is only there for activities that will benefit her or activities that involve drinking or drugs.