There is no such thing in the world that stay forever. And personally, I would never choose to live forever in this world for everything has its own lifespan and there is a right time for everything if we must have to go then we must have to accept it. We don't need to be afraid to die for we can have an everlasting life in heaven if we only obey God's commandment while we're still here in this world. There an everlasting life in heaven with no pain and sorrow only love and joy.
This is a very interesting question, very deep. Personally, I wouldn't like to live forever as you would see everyone around you that you care about die. I think a decent age like 85 or so is a good one to aim for.
I want to live forever in a state wherein there are no pain, no disappointment, no hurt, and no harassment. I not meaning an earthly eternal life, but a heavenly one instead. Every person here will soon be gone in this earth, and each of us will face judgment from God, accounting for all the things that we did since we were born. our destination will either be only in heaven or hell. We all have a will to make things right with God. It is up to us if we listen to Him or not.
This is a very deep, interesting question. Personally, I would want to live forever as there is so much to do and see in a short period of time. There are 195 countries in the world, I'd like to go travelling and see as much of the world as I can and experience as many different experiences as possible.