OK, this is a given, and probably the reason you became friends in the first place. But there's a lot to be said for chemistry and shared interests.
As for fun, it depends how you define it: Some friends are fun because they're the life of the party, others are fun because they notice every strange little detail about a situation. Some people are fun simply because they see life like no one else does.
3. A good friend is attentive and adaptable.
A good friend is at least a fairly good listener and notices how little, day-to-day things affect you. They can't read your mind, but chances are they can usually tell when you're happy, sad, excited, shocked or upset. If they're aware that they're doing something that annoys you, they try to change their ways or at least talk to you about it.
4. A good friend is supportive of you and your goals.
Sure, your friend may think you're cool, but are they on the same page as you? Do they know what you want most out of life? A really good friend will know what makes you tick and help you become the person you want to be. They won't try to change who you are or drag you into situations that make you uncomfortable or put you at risk of losing something that matters to you.
5. A good friend is a friend you can trust.
A true friend won't try to steal your girlfriend or boyfriend, your job or your personality. They won't gossip about you constantly or try to damage your reputation. They will let you know when they're concerned and do their best to stick up for you when you're in trouble.
6. A good friend makes it clear that they care about you.
Different people may have different ways of letting you know that they care about you. One person may give you a big hug whereas another person might gently tease you. A big clue that someone cares is that they talk to you fairly often and, in general, know what's going on in your life and act interested about it.
7. A good friend sticks with you in good times and bad.
Loyalty is a quality almost everyone lists when asked what they look for in a friend. A loyal friend will stick with you when your new play is a flop, when you bomb the SATs or when your parents get divorced. If you move or switch schools, they'll do their best to stay in touch with you.
8. A good friend accepts you for who you are, even when you're being a butthead.
In friendship, being accepting goes hand in hand with being loyal. A true friend rolls with the punches as you grow and change and know how to deal with your quirks and faults.
They are also patient with you when you make mistakes -- even big ones -- and learn how to forgive you when you hurt them. In other words, they treat you as you'd like to be treated, even when you aren't at your best.