You must remember that those people who are good to you might not necessarily be people who are good for you.
The latter has to be people who can (or knows it is important to) edify you, allowing you to grow better in your character, help you reach for your goals and dreams and strengthen you with joy when you need it the most. This people should be more than just nice people. They are committed people. People who will have a special place in your heart.
And then, you do the same. This is how lasting relationships work.