The first thing I'd say is that I feel sorry for you -- because without God you'll miss life's greatest joy. He alone gives lasting meaning and purpose to life, and He alone can make our lives complete. After all, He made us, and He knows what is best for us.
But I'd also urge you to reconsider whether or not you need God. No, you may not feel that you need Him, but could your feelings be deceiving you? How do you know, for example, whether or not the road you're on is the right one? Or what will you do when that road turns bumpy -- when your relationships turn sour, or your health deteriorates, or all your plans fail? Where will you turn? Most of all, where will you turn for hope and assurance when death stares you in the face?
Let me challenge you to do two things. First, I challenge you to pray. That may sound strange, but I challenge you to ask God to show you if you need Him, and to give you a desire to put your life into His hands. The Bible says, "Seek the Lord while he may be found; call on him while he is near" (Isaiah 55:6).
Second, I challenge you to look at Jesus Christ. If you're like most people, you haven't thought much about Him or investigated His life and teachings, but I challenge you to do so. Read through one of the Gospels (I suggest John) and discover who He is and what difference He can make in your life. Your life will never be the same.